Merge pull request #573 from kohler/kwork

Fix atom-spacing, add text-mode fonts, and miscellany

src/Options.js

@@ -99,7 +99,7 @@ Options.prototype.withPhantom = function() {
  */
 Options.prototype.withFont = function(font) {
     return this.extend({
-        font: font,
+        font: font || this.font,
     });
 };
 

src/buildCommon.js

@@ -36,6 +36,8 @@ var mainitLetters = [
  * classes to be attached to the node.
  *
  * TODO: make argument order closer to makeSpan
+ * TODO: add a separate argument for math class (e.g. `mop`, `mbin`), which
+ * should if present come first in `classes`.
  */
 var makeSymbol = function(value, fontFamily, mode, options, classes) {
     // Replace the value with its replaced value from symbol.js
@@ -47,8 +49,12 @@ var makeSymbol = function(value, fontFamily, mode, options, classes) {
 
     var symbolNode;
     if (metrics) {
+        var italic = metrics.italic;
+        if (mode === "text") {
+            italic = 0;
+        }
         symbolNode = new domTree.symbolNode(
-            value, metrics.height, metrics.depth, metrics.italic, metrics.skew,
+            value, metrics.height, metrics.depth, italic, metrics.skew,
             classes);
     } else {
         // TODO(emily): Figure out a good way to only print this in development
@@ -183,6 +189,8 @@ var sizeElementFromChildren = function(elem) {
  *
  * TODO: Ensure that `options` is always provided (currently some call sites
  * don't pass it).
+ * TODO: add a separate argument for math class (e.g. `mop`, `mbin`), which
+ * should if present come first in `classes`.
  */
 var makeSpan = function(classes, children, options) {
     var span = new domTree.span(classes, children, options);
@@ -422,6 +430,10 @@ var fontMap = {
         variant: "normal",
         fontName: "Main-Regular",
     },
+    "textit": {
+        variant: "italic",
+        fontName: "Main-Italic",
+    },
 
     // "mathit" is missing because it requires the use of two fonts: Main-Italic
     // and Math-Italic.  This is handled by a special case in makeOrd which ends

src/buildHTML.js

@@ -21,27 +21,52 @@ var isSpace = function(node) {
     return node instanceof domTree.span && node.classes[0] === "mspace";
 };
 
+// Binary atoms (first class `mbin`) change into ordinary atoms (`mord`)
+// depending on their surroundings. See TeXbook pg. 442-446, Rules 5 and 6,
+// and the text before Rule 19.
+
+var isBin = function(node) {
+    return node && node.classes[0] === "mbin";
+};
+
+var isBinLeftCanceller = function(node, isRealGroup) {
+    // TODO: This code assumes that a node's math class is the first element
+    // of its `classes` array. A later cleanup should ensure this, for
+    // instance by changing the signature of `makeSpan`.
+    if (node) {
+        return utils.contains(["mbin", "mopen", "mrel", "mop", "mpunct"],
+                              node.classes[0]);
+    } else {
+        return isRealGroup;
+    }
+};
+
+var isBinRightCanceller = function(node, isRealGroup) {
+    if (node) {
+        return utils.contains(["mrel", "mclose", "mpunct"], node.classes[0]);
+    } else {
+        return isRealGroup;
+    }
+};
+
 /**
  * Take a list of nodes, build them in order, and return a list of the built
- * nodes. This function handles the `prev` node correctly, and passes the
+ * nodes. documentFragments are flattened into their contents, so the
- * previous element from the list as the prev of the next element, ignoring
+ * returned list contains no fragments. `isRealGroup` is true if `expression`
- * spaces. documentFragments are flattened into their contents, so the
+ * is a real group (no atoms will be added on either side), as opposed to
- * returned list contains no fragments.
+ * a partial group (e.g. one created by \color).
  */
-var buildExpression = function(expression, options, prev) {
+var buildExpression = function(expression, options, isRealGroup) {
     // Parse expressions into `groups`.
     var groups = [];
     for (var i = 0; i < expression.length; i++) {
         var group = expression[i];
-        var output = buildGroup(group, options, prev);
+        var output = buildGroup(group, options);
         if (output instanceof domTree.documentFragment) {
             Array.prototype.push.apply(groups, output.children);
         } else {
             groups.push(output);
         }
-        if (!isSpace(output)) {
-            prev = group;
-        }
     }
     // At this point `groups` consists entirely of `symbolNode`s and `span`s.
 
@@ -68,69 +93,32 @@ var buildExpression = function(expression, options, prev) {
         Array.prototype.push.apply(groups, spaces);
     }
 
+    // Binary operators change to ordinary symbols in some contexts.
+    for (i = 0; i < groups.length; i++) {
+        if (isBin(groups[i])
+            && (isBinLeftCanceller(groups[i - 1], isRealGroup)
+                || isBinRightCanceller(groups[i + 1], isRealGroup))) {
+            groups[i].classes[0] = "mord";
+        }
+    }
+
     return groups;
 };
 
-// List of types used by getTypeOfGroup,
+// Return math atom class (mclass) of a domTree.
-// see https://github.com/Khan/KaTeX/wiki/Examining-TeX#group-types
+var getTypeOfDomTree = function(node) {
-var groupToType = {
+    if (node instanceof domTree.documentFragment) {
-    mathord: "mord",
+        if (node.children.length) {
-    textord: "mord",
+            return getTypeOfDomTree(
-    bin: "mbin",
+                node.children[node.children.length - 1]);
-    rel: "mrel",
-    text: "mord",
-    open: "mopen",
-    close: "mclose",
-    inner: "minner",
-    genfrac: "mord",
-    array: "mord",
-    spacing: "mord",
-    punct: "mpunct",
-    ordgroup: "mord",
-    op: "mop",
-    katex: "mord",
-    overline: "mord",
-    underline: "mord",
-    rule: "mord",
-    leftright: "minner",
-    sqrt: "mord",
-    accent: "mord",
-};
-
-/**
- * Gets the final math type of an expression, given its group type. This type is
- * used to determine spacing between elements, and affects bin elements by
- * causing them to change depending on what types are around them. This type
- * must be attached to the outermost node of an element as a CSS class so that
- * spacing with its surrounding elements works correctly.
- *
- * Some elements can be mapped one-to-one from group type to math type, and
- * those are listed in the `groupToType` table.
- *
- * Others (usually elements that wrap around other elements) often have
- * recursive definitions, and thus call `getTypeOfGroup` on their inner
- * elements.
- */
-var getTypeOfGroup = function(group) {
-    if (group == null) {
-        // Like when typesetting $^3$
-        return groupToType.mathord;
-    } else if (group.type === "supsub") {
-        return getTypeOfGroup(group.value.base);
-    } else if (group.type === "llap" || group.type === "rlap") {
-        return getTypeOfGroup(group.value);
-    } else if (group.type === "color" || group.type === "sizing"
-               || group.type === "styling") {
-        // Return type of rightmost element of group.
-        var atoms = group.value.value;
-        return getTypeOfGroup(atoms[atoms.length - 1]);
-    } else if (group.type === "font") {
-        return getTypeOfGroup(group.value.body);
-    } else if (group.type === "delimsizing") {
-        return groupToType[group.value.delimType];
-    } else {
-        return groupToType[group.type];
         }
+    } else {
+        if (utils.contains(["mord", "mop", "mbin", "mrel", "mopen", "mclose",
+                            "mpunct", "minner"], node.classes[0])) {
+            return node.classes[0];
+        }
+    }
+    return null;
 };
 
 /**
@@ -201,12 +189,11 @@ var isCharacterBox = function(group) {
         baseElem.type === "punct";
 };
 
-var makeNullDelimiter = function(options) {
+var makeNullDelimiter = function(options, classes) {
-    return makeSpan([
+    return makeSpan(classes.concat([
         "sizing", "reset-" + options.size, "size5",
         options.style.reset(), Style.TEXT.cls(),
-        "nulldelimiter",
+        "nulldelimiter"]));
-    ]);
 };
 
 /**
@@ -215,81 +202,70 @@ var makeNullDelimiter = function(options) {
  */
 var groupTypes = {};
 
-groupTypes.mathord = function(group, options, prev) {
+groupTypes.mathord = function(group, options) {
     return buildCommon.makeOrd(group, options, "mathord");
 };
 
-groupTypes.textord = function(group, options, prev) {
+groupTypes.textord = function(group, options) {
     return buildCommon.makeOrd(group, options, "textord");
 };
 
-groupTypes.bin = function(group, options, prev) {
+groupTypes.bin = function(group, options) {
-    var className = "mbin";
-    // Pull out the most recent element. Do some special handling to find
-    // things at the end of a \color group. Note that we don't use the same
-    // logic for ordgroups (which count as ords).
-    var prevAtom = prev;
-    while (prevAtom && prevAtom.type === "color") {
-        var atoms = prevAtom.value.value;
-        prevAtom = atoms[atoms.length - 1];
-    }
-    // See TeXbook pg. 442-446, Rules 5 and 6, and the text before Rule 19.
-    // Here, we determine whether the bin should turn into an ord. We
-    // currently only apply Rule 5.
-    if (!prev || utils.contains(["mbin", "mopen", "mrel", "mop", "mpunct"],
-            getTypeOfGroup(prevAtom))) {
-        group.type = "textord";
-        className = "mord";
-    }
-
     return buildCommon.mathsym(
-        group.value, group.mode, options, [className]);
+        group.value, group.mode, options, ["mbin"]);
 };
 
-groupTypes.rel = function(group, options, prev) {
+groupTypes.rel = function(group, options) {
     return buildCommon.mathsym(
         group.value, group.mode, options, ["mrel"]);
 };
 
-groupTypes.open = function(group, options, prev) {
+groupTypes.open = function(group, options) {
     return buildCommon.mathsym(
         group.value, group.mode, options, ["mopen"]);
 };
 
-groupTypes.close = function(group, options, prev) {
+groupTypes.close = function(group, options) {
     return buildCommon.mathsym(
         group.value, group.mode, options, ["mclose"]);
 };
 
-groupTypes.inner = function(group, options, prev) {
+groupTypes.inner = function(group, options) {
     return buildCommon.mathsym(
         group.value, group.mode, options, ["minner"]);
 };
 
-groupTypes.punct = function(group, options, prev) {
+groupTypes.punct = function(group, options) {
     return buildCommon.mathsym(
         group.value, group.mode, options, ["mpunct"]);
 };
 
-groupTypes.ordgroup = function(group, options, prev) {
+groupTypes.ordgroup = function(group, options) {
     return makeSpan(
         ["mord", options.style.cls()],
-        buildExpression(group.value, options.reset()),
+        buildExpression(group.value, options.reset(), true),
         options
     );
 };
 
-groupTypes.text = function(group, options, prev) {
+groupTypes.text = function(group, options) {
-    return makeSpan(["mord", "text", options.style.cls()],
+    var newOptions = options.withFont(group.value.style);
-        buildExpression(group.value.body, options.reset()),
+    var inner = buildExpression(group.value.body, newOptions, true);
-        options);
+    for (var i = 0; i < inner.length - 1; i++) {
+        if (inner[i].tryCombine(inner[i + 1])) {
+            inner.splice(i + 1, 1);
+            i--;
+        }
+    }
+    return makeSpan(["mord", "text", newOptions.style.cls()],
+        inner, newOptions);
 };
 
-groupTypes.color = function(group, options, prev) {
+groupTypes.color = function(group, options) {
     var elements = buildExpression(
         group.value.value,
         options.withColor(group.value.color),
-        prev
+        false
     );
 
     // \color isn't supposed to affect the type of the elements it contains.
@@ -299,14 +275,14 @@ groupTypes.color = function(group, options, prev) {
     return new buildCommon.makeFragment(elements);
 };
 
-groupTypes.supsub = function(group, options, prev) {
+groupTypes.supsub = function(group, options) {
     // Superscript and subscripts are handled in the TeXbook on page
     // 445-446, rules 18(a-f).
 
     // Here is where we defer to the inner group if it should handle
     // superscripts and subscripts itself.
     if (shouldHandleSupSub(group.value.base, options)) {
-        return groupTypes[group.value.base.type](group, options, prev);
+        return groupTypes[group.value.base.type](group, options);
     }
 
     var base = buildGroup(group.value.base, options.reset());
@@ -422,12 +398,13 @@ groupTypes.supsub = function(group, options, prev) {
     }
 
     // We ensure to wrap the supsub vlist in a span.msupsub to reset text-align
-    return makeSpan([getTypeOfGroup(group.value.base)],
+    var mclass = getTypeOfDomTree(base) || "mord";
+    return makeSpan([mclass],
         [base, makeSpan(["msupsub"], [supsub])],
         options);
 };
 
-groupTypes.genfrac = function(group, options, prev) {
+groupTypes.genfrac = function(group, options) {
     // Fractions are handled in the TeXbook on pages 444-445, rules 15(a-e).
     // Figure out what style this fraction should be in based on the
     // function used
@@ -546,18 +523,18 @@ groupTypes.genfrac = function(group, options, prev) {
     var leftDelim;
     var rightDelim;
     if (group.value.leftDelim == null) {
-        leftDelim = makeNullDelimiter(options);
+        leftDelim = makeNullDelimiter(options, ["mopen"]);
     } else {
         leftDelim = delimiter.customSizedDelim(
             group.value.leftDelim, delimSize, true,
-            options.withStyle(style), group.mode);
+            options.withStyle(style), group.mode, ["mopen"]);
     }
     if (group.value.rightDelim == null) {
-        rightDelim = makeNullDelimiter(options);
+        rightDelim = makeNullDelimiter(options, ["mclose"]);
     } else {
         rightDelim = delimiter.customSizedDelim(
             group.value.rightDelim, delimSize, true,
-            options.withStyle(style), group.mode);
+            options.withStyle(style), group.mode, ["mclose"]);
     }
 
     return makeSpan(
@@ -566,7 +543,7 @@ groupTypes.genfrac = function(group, options, prev) {
         options);
 };
 
-groupTypes.array = function(group, options, prev) {
+groupTypes.array = function(group, options) {
     var r;
     var c;
     var nr = group.value.body.length;
@@ -730,47 +707,51 @@ groupTypes.array = function(group, options, prev) {
     return makeSpan(["mord"], [body], options);
 };
 
-groupTypes.spacing = function(group, options, prev) {
+groupTypes.spacing = function(group, options) {
     if (group.value === "\\ " || group.value === "\\space" ||
         group.value === " " || group.value === "~") {
         // Spaces are generated by adding an actual space. Each of these
         // things has an entry in the symbols table, so these will be turned
         // into appropriate outputs.
-        return makeSpan(
+        if (group.mode === "text") {
-            ["mspace"],
+            return buildCommon.makeOrd(group, options, "textord");
-            [buildCommon.mathsym(group.value, group.mode)]
+        } else {
-        );
+            return makeSpan(["mspace"],
+                [buildCommon.mathsym(group.value, group.mode, options)],
+                options);
+        }
     } else {
         // Other kinds of spaces are of arbitrary width. We use CSS to
         // generate these.
         return makeSpan(
             ["mspace",
-             buildCommon.spacingFunctions[group.value].className]);
+             buildCommon.spacingFunctions[group.value].className],
+            [], options);
     }
 };
 
-groupTypes.llap = function(group, options, prev) {
+groupTypes.llap = function(group, options) {
     var inner = makeSpan(
         ["inner"], [buildGroup(group.value.body, options.reset())]);
     var fix = makeSpan(["fix"], []);
     return makeSpan(
-        ["llap", options.style.cls()], [inner, fix], options);
+        ["mord", "llap", options.style.cls()], [inner, fix], options);
 };
 
-groupTypes.rlap = function(group, options, prev) {
+groupTypes.rlap = function(group, options) {
     var inner = makeSpan(
         ["inner"], [buildGroup(group.value.body, options.reset())]);
     var fix = makeSpan(["fix"], []);
     return makeSpan(
-        ["rlap", options.style.cls()], [inner, fix], options);
+        ["mord", "rlap", options.style.cls()], [inner, fix], options);
 };
 
-groupTypes.op = function(group, options, prev) {
+groupTypes.op = function(group, options) {
     // Operators are handled in the TeXbook pg. 443-444, rule 13(a).
     var supGroup;
     var subGroup;
     var hasLimits = false;
-    if (group.type === "supsub" ) {
+    if (group.type === "supsub") {
         // If we have limits, supsub will pass us its group to handle. Pull
         // out the superscript and subscript and set the group to the op in
         // its base.
@@ -816,6 +797,11 @@ groupTypes.op = function(group, options, prev) {
 
         // The slant of the symbol is just its italic correction.
         slant = base.italic;
+    } else if (group.value.value) {
+        // If this is a list, compose that list.
+        var inner = buildExpression(group.value.value, options, true);
+
+        base = makeSpan(["mop"], inner, options);
     } else {
         // Otherwise, this is a text operator. Build the text from the
         // operator's name.
@@ -930,7 +916,7 @@ groupTypes.op = function(group, options, prev) {
     }
 };
 
-groupTypes.katex = function(group, options, prev) {
+groupTypes.katex = function(group, options) {
     // The KaTeX logo. The offsets for the K and a were chosen to look
     // good, but the offsets for the T, E, and X were taken from the
     // definition of \TeX in TeX (see TeXbook pg. 356)
@@ -957,7 +943,7 @@ groupTypes.katex = function(group, options, prev) {
         ["mord", "katex-logo"], [k, a, t, e, x], options);
 };
 
-groupTypes.overline = function(group, options, prev) {
+groupTypes.overline = function(group, options) {
     // Overlines are handled in the TeXbook pg 443, Rule 9.
     var style = options.style;
 
@@ -985,7 +971,7 @@ groupTypes.overline = function(group, options, prev) {
     return makeSpan(["mord", "overline"], [vlist], options);
 };
 
-groupTypes.underline = function(group, options, prev) {
+groupTypes.underline = function(group, options) {
     // Underlines are handled in the TeXbook pg 443, Rule 10.
     var style = options.style;
 
@@ -1011,7 +997,7 @@ groupTypes.underline = function(group, options, prev) {
     return makeSpan(["mord", "underline"], [vlist], options);
 };
 
-groupTypes.sqrt = function(group, options, prev) {
+groupTypes.sqrt = function(group, options) {
     // Square roots are handled in the TeXbook pg. 443, Rule 11.
     var style = options.style;
 
@@ -1110,12 +1096,12 @@ groupTypes.sqrt = function(group, options, prev) {
     }
 };
 
-groupTypes.sizing = function(group, options, prev) {
+groupTypes.sizing = function(group, options) {
     // Handle sizing operators like \Huge. Real TeX doesn't actually allow
     // these functions inside of math expressions, so we do some special
     // handling.
     var inner = buildExpression(group.value.value,
-            options.withSize(group.value.size), prev);
+            options.withSize(group.value.size), false);
 
     // Compute the correct maxFontSize.
     var style = options.style;
@@ -1141,7 +1127,7 @@ groupTypes.sizing = function(group, options, prev) {
     return buildCommon.makeFragment(inner);
 };
 
-groupTypes.styling = function(group, options, prev) {
+groupTypes.styling = function(group, options) {
     // Style changes are handled in the TeXbook on pg. 442, Rule 3.
 
     // Figure out what style we're changing to.
@@ -1157,7 +1143,7 @@ groupTypes.styling = function(group, options, prev) {
 
     // Build the inner expression in the new style.
     var inner = buildExpression(
-        group.value.value, newOptions, prev);
+        group.value.value, newOptions, false);
 
     // Add style-resetting classes to the inner list. Handle nested changes.
     for (var i = 0; i < inner.length; i++) {
@@ -1174,31 +1160,29 @@ groupTypes.styling = function(group, options, prev) {
     return new buildCommon.makeFragment(inner);
 };
 
-groupTypes.font = function(group, options, prev) {
+groupTypes.font = function(group, options) {
     var font = group.value.font;
-    return buildGroup(group.value.body, options.withFont(font), prev);
+    return buildGroup(group.value.body, options.withFont(font));
 };
 
-groupTypes.delimsizing = function(group, options, prev) {
+groupTypes.delimsizing = function(group, options) {
     var delim = group.value.value;
 
     if (delim === ".") {
         // Empty delimiters still count as elements, even though they don't
         // show anything.
-        return makeSpan([groupToType[group.value.delimType]]);
+        return makeSpan([group.value.mclass]);
     }
 
     // Use delimiter.sizedDelim to generate the delimiter.
-    return makeSpan(
+    return delimiter.sizedDelim(
-        [groupToType[group.value.delimType]],
+            delim, group.value.size, options, group.mode,
-        [delimiter.sizedDelim(
+            [group.value.mclass]);
-            delim, group.value.size, options, group.mode)],
-        options);
 };
 
-groupTypes.leftright = function(group, options, prev) {
+groupTypes.leftright = function(group, options) {
     // Build the inner expression
-    var inner = buildExpression(group.value.body, options.reset());
+    var inner = buildExpression(group.value.body, options.reset(), true);
 
     var innerHeight = 0;
     var innerDepth = 0;
@@ -1220,13 +1204,13 @@ groupTypes.leftright = function(group, options, prev) {
     var leftDelim;
     if (group.value.left === ".") {
         // Empty delimiters in \left and \right make null delimiter spaces.
-        leftDelim = makeNullDelimiter(options);
+        leftDelim = makeNullDelimiter(options, ["mopen"]);
     } else {
         // Otherwise, use leftRightDelim to generate the correct sized
         // delimiter.
         leftDelim = delimiter.leftRightDelim(
             group.value.left, innerHeight, innerDepth, options,
-            group.mode);
+            group.mode, ["mopen"]);
     }
     // Add it to the beginning of the expression
     inner.unshift(leftDelim);
@@ -1234,11 +1218,11 @@ groupTypes.leftright = function(group, options, prev) {
     var rightDelim;
     // Same for the right delimiter
     if (group.value.right === ".") {
-        rightDelim = makeNullDelimiter(options);
+        rightDelim = makeNullDelimiter(options, ["mclose"]);
     } else {
         rightDelim = delimiter.leftRightDelim(
             group.value.right, innerHeight, innerDepth, options,
-            group.mode);
+            group.mode, ["mclose"]);
     }
     // Add it to the end of the expression.
     inner.push(rightDelim);
@@ -1247,7 +1231,7 @@ groupTypes.leftright = function(group, options, prev) {
         ["minner", style.cls()], inner, options);
 };
 
-groupTypes.rule = function(group, options, prev) {
+groupTypes.rule = function(group, options) {
     // Make an empty span for the rule
     var rule = makeSpan(["mord", "rule"], [], options);
     var style = options.style;
@@ -1290,7 +1274,7 @@ groupTypes.rule = function(group, options, prev) {
     return rule;
 };
 
-groupTypes.kern = function(group, options, prev) {
+groupTypes.kern = function(group, options) {
     // Make an empty span for the rule
     var rule = makeSpan(["mord", "rule"], [], options);
     var style = options.style;
@@ -1310,7 +1294,7 @@ groupTypes.kern = function(group, options, prev) {
     return rule;
 };
 
-groupTypes.accent = function(group, options, prev) {
+groupTypes.accent = function(group, options) {
     // Accents are handled in the TeXbook pg. 443, rule 12.
     var base = group.value.base;
     var style = options.style;
@@ -1337,7 +1321,7 @@ groupTypes.accent = function(group, options, prev) {
         // Rerender the supsub group with its new base, and store that
         // result.
         supsubGroup = buildGroup(
-            supsub, options.reset(), prev);
+            supsub, options.reset());
     }
 
     // Build the base group
@@ -1419,11 +1403,11 @@ groupTypes.accent = function(group, options, prev) {
     }
 };
 
-groupTypes.phantom = function(group, options, prev) {
+groupTypes.phantom = function(group, options) {
     var elements = buildExpression(
         group.value.value,
         options.withPhantom(),
-        prev
+        false
     );
 
     // \phantom isn't supposed to affect the elements it contains.
@@ -1431,19 +1415,25 @@ groupTypes.phantom = function(group, options, prev) {
     return new buildCommon.makeFragment(elements);
 };
 
+groupTypes.mclass = function(group, options) {
+    var elements = buildExpression(group.value.value, options, true);
+
+    return makeSpan([group.value.mclass], elements, options);
+};
+
 /**
  * buildGroup is the function that takes a group and calls the correct groupType
  * function for it. It also handles the interaction of size and style changes
  * between parents and children.
  */
-var buildGroup = function(group, options, prev) {
+var buildGroup = function(group, options) {
     if (!group) {
         return makeSpan();
     }
 
     if (groupTypes[group.type]) {
         // Call the groupTypes function
-        var groupNode = groupTypes[group.type](group, options, prev);
+        var groupNode = groupTypes[group.type](group, options);
         var multiplier;
 
         // If the style changed between the parent and the current group,
@@ -1483,7 +1473,7 @@ var buildHTML = function(tree, options) {
     tree = JSON.parse(JSON.stringify(tree));
 
     // Build the expression contained in the tree
-    var expression = buildExpression(tree, options);
+    var expression = buildExpression(tree, options, true);
     var body = makeSpan(["base", options.style.cls()], expression, options);
 
     // Add struts, which ensure that the top of the HTML element falls at the

src/buildMathML.js

@@ -316,7 +316,7 @@ groupTypes.spacing = function(group) {
     return node;
 };
 
-groupTypes.op = function(group) {
+groupTypes.op = function(group, options) {
     var node;
 
     // TODO(emily): handle big operators using the `largeop` attribute
@@ -325,6 +325,10 @@ groupTypes.op = function(group) {
         // This is a symbol. Just add the symbol.
         node = new mathMLTree.MathNode(
             "mo", [makeText(group.value.body, group.mode)]);
+    } else if (group.value.value) {
+        // This is an operator with children. Add them.
+        node = new mathMLTree.MathNode(
+            "mo", buildExpression(group.value.value, options));
     } else {
         // This is a text operator. Add all of the characters from the
         // operator's name.
@@ -358,10 +362,10 @@ groupTypes.delimsizing = function(group) {
 
     var node = new mathMLTree.MathNode("mo", children);
 
-    if (group.value.delimType === "open" ||
+    if (group.value.mclass === "mopen" ||
-        group.value.delimType === "close") {
+        group.value.mclass === "mclose") {
         // Only some of the delimsizing functions act as fences, and they
-        // return "open" or "close" delimTypes.
+        // return "mopen" or "mclose" mclass.
         node.setAttribute("fence", "true");
     } else {
         // Explicitly disable fencing if it's not a fence, to override the
@@ -470,11 +474,16 @@ groupTypes.rlap = function(group, options) {
     return node;
 };
 
-groupTypes.phantom = function(group, options, prev) {
+groupTypes.phantom = function(group, options) {
     var inner = buildExpression(group.value.value, options);
     return new mathMLTree.MathNode("mphantom", inner);
 };
 
+groupTypes.mclass = function(group, options) {
+    var inner = buildExpression(group.value.value, options);
+    return new mathMLTree.MathNode("mstyle", inner);
+};
+
 /**
  * Takes a list of nodes, builds them, and returns a list of the generated
  * MathML nodes. A little simpler than the HTML version because we don't do any

src/delimiter.js

@@ -56,9 +56,11 @@ var mathrmSize = function(value, size, mode, options) {
  * Puts a delimiter span in a given style, and adds appropriate height, depth,
  * and maxFontSizes.
  */
-var styleWrap = function(delim, toStyle, options) {
+var styleWrap = function(delim, toStyle, options, classes) {
+    classes = classes || [];
     var span = makeSpan(
-        ["style-wrap", options.style.reset(), toStyle.cls()], [delim], options);
+        classes.concat(["style-wrap", options.style.reset(), toStyle.cls()]),
+        [delim], options);
 
     var multiplier = toStyle.sizeMultiplier / options.style.sizeMultiplier;
 
@@ -74,10 +76,10 @@ var styleWrap = function(delim, toStyle, options) {
  * font, but is restyled to either be in textstyle, scriptstyle, or
  * scriptscriptstyle.
  */
-var makeSmallDelim = function(delim, style, center, options, mode) {
+var makeSmallDelim = function(delim, style, center, options, mode, classes) {
     var text = buildCommon.makeSymbol(delim, "Main-Regular", mode, options);
 
-    var span = styleWrap(text, style, options);
+    var span = styleWrap(text, style, options, classes);
 
     if (center) {
         var shift =
@@ -96,13 +98,12 @@ var makeSmallDelim = function(delim, style, center, options, mode) {
  * Makes a large delimiter. This is a delimiter that comes in the Size1, Size2,
  * Size3, or Size4 fonts. It is always rendered in textstyle.
  */
-var makeLargeDelim = function(delim, size, center, options, mode) {
+var makeLargeDelim = function(delim, size, center, options, mode, classes) {
     var inner = mathrmSize(delim, size, mode, options);
 
     var span = styleWrap(
-        makeSpan(["delimsizing", "size" + size],
+        makeSpan(["delimsizing", "size" + size], [inner], options),
-                 [inner], options),
+        Style.TEXT, options, classes);
-        Style.TEXT, options);
 
     if (center) {
         var shift = (1 - options.style.sizeMultiplier) *
@@ -142,7 +143,8 @@ var makeInner = function(symbol, font, mode) {
  * Make a stacked delimiter out of a given delimiter, with the total height at
  * least `heightTotal`. This routine is mentioned on page 442 of the TeXbook.
  */
-var makeStackedDelim = function(delim, heightTotal, center, options, mode) {
+var makeStackedDelim = function(delim, heightTotal, center, options, mode,
+                                classes) {
     // There are four parts, the top, an optional middle, a repeated part, and a
     // bottom.
     var top;
@@ -320,7 +322,7 @@ var makeStackedDelim = function(delim, heightTotal, center, options, mode) {
 
     return styleWrap(
         makeSpan(["delimsizing", "mult"], [inner], options),
-        Style.TEXT, options);
+        Style.TEXT, options, classes);
 };
 
 // There are three kinds of delimiters, delimiters that stack when they become
@@ -354,7 +356,7 @@ var sizeToMaxHeight = [0, 1.2, 1.8, 2.4, 3.0];
 /**
  * Used to create a delimiter of a specific size, where `size` is 1, 2, 3, or 4.
  */
-var makeSizedDelim = function(delim, size, options, mode) {
+var makeSizedDelim = function(delim, size, options, mode, classes) {
     // < and > turn into \langle and \rangle in delimiters
     if (delim === "<" || delim === "\\lt") {
         delim = "\\langle";
@@ -365,10 +367,10 @@ var makeSizedDelim = function(delim, size, options, mode) {
     // Sized delimiters are never centered.
     if (utils.contains(stackLargeDelimiters, delim) ||
         utils.contains(stackNeverDelimiters, delim)) {
-        return makeLargeDelim(delim, size, false, options, mode);
+        return makeLargeDelim(delim, size, false, options, mode, classes);
     } else if (utils.contains(stackAlwaysDelimiters, delim)) {
         return makeStackedDelim(
-            delim, sizeToMaxHeight[size], false, options, mode);
+            delim, sizeToMaxHeight[size], false, options, mode, classes);
     } else {
         throw new ParseError("Illegal delimiter: '" + delim + "'");
     }
@@ -471,7 +473,8 @@ var traverseSequence = function(delim, height, sequence, options) {
  * Make a delimiter of a given height+depth, with optional centering. Here, we
  * traverse the sequences, and create a delimiter that the sequence tells us to.
  */
-var makeCustomSizedDelim = function(delim, height, center, options, mode) {
+var makeCustomSizedDelim = function(delim, height, center, options, mode,
+                                    classes) {
     if (delim === "<" || delim === "\\lt") {
         delim = "\\langle";
     } else if (delim === ">" || delim === "\\gt") {
@@ -494,11 +497,13 @@ var makeCustomSizedDelim = function(delim, height, center, options, mode) {
     // Depending on the sequence element we decided on, call the appropriate
     // function.
     if (delimType.type === "small") {
-        return makeSmallDelim(delim, delimType.style, center, options, mode);
+        return makeSmallDelim(delim, delimType.style, center, options, mode,
+                              classes);
     } else if (delimType.type === "large") {
-        return makeLargeDelim(delim, delimType.size, center, options, mode);
+        return makeLargeDelim(delim, delimType.size, center, options, mode,
+                              classes);
     } else if (delimType.type === "stack") {
-        return makeStackedDelim(delim, height, center, options, mode);
+        return makeStackedDelim(delim, height, center, options, mode, classes);
     }
 };
 
@@ -506,7 +511,8 @@ var makeCustomSizedDelim = function(delim, height, center, options, mode) {
  * Make a delimiter for use with `\left` and `\right`, given a height and depth
  * of an expression that the delimiters surround.
  */
-var makeLeftRightDelim = function(delim, height, depth, options, mode) {
+var makeLeftRightDelim = function(delim, height, depth, options, mode,
+                                  classes) {
     // We always center \left/\right delimiters, so the axis is always shifted
     var axisHeight =
         options.style.metrics.axisHeight * options.style.sizeMultiplier;
@@ -533,7 +539,8 @@ var makeLeftRightDelim = function(delim, height, depth, options, mode) {
 
     // Finally, we defer to `makeCustomSizedDelim` with our calculated total
     // height
-    return makeCustomSizedDelim(delim, totalHeight, true, options, mode);
+    return makeCustomSizedDelim(delim, totalHeight, true, options, mode,
+                                classes);
 };
 
 module.exports = {

src/domTree.js

@@ -57,6 +57,10 @@ span.prototype.setAttribute = function(attribute, value) {
     this.attributes[attribute] = value;
 };
 
+span.prototype.tryCombine = function(sibling) {
+    return false;
+};
+
 /**
  * Convert the span into an HTML node
  */
@@ -220,6 +224,34 @@ function symbolNode(value, height, depth, italic, skew, classes, style) {
     }
 }
 
+symbolNode.prototype.tryCombine = function(sibling) {
+    if (!sibling
+        || !(sibling instanceof symbolNode)
+        || this.italic > 0
+        || createClass(this.classes) !== createClass(sibling.classes)
+        || this.skew !== sibling.skew
+        || this.maxFontSize !== sibling.maxFontSize) {
+        return false;
+    }
+    for (var style in this.style) {
+        if (this.style.hasOwnProperty(style)
+            && this.style[style] !== sibling.style[style]) {
+            return false;
+        }
+    }
+    for (style in sibling.style) {
+        if (sibling.style.hasOwnProperty(style)
+            && this.style[style] !== sibling.style[style]) {
+            return false;
+        }
+    }
+    this.value += sibling.value;
+    this.height = Math.max(this.height, sibling.height);
+    this.depth = Math.max(this.depth, sibling.depth);
+    this.italic = sibling.italic;
+    return true;
+};
+
 /**
  * Creates a text node or span from a symbol node. Note that a span is only
  * created if it is needed.

src/functions.js

@@ -1,5 +1,7 @@
 var utils = require("./utils");
 var ParseError = require("./ParseError");
+var parseData = require("./parseData");
+var ParseNode = parseData.ParseNode;
 
 /* This file contains a list of functions that we parse, identified by
  * the calls to defineFunction.
@@ -100,6 +102,16 @@ function defineFunction(names, props, handler) {
     }
 }
 
+// Since the corresponding buildHTML/buildMathML function expects a
+// list of elements, we normalize for different kinds of arguments
+var ordargument = function(arg) {
+    if (arg.type === "ordgroup") {
+        return arg.value;
+    } else {
+        return [arg];
+    }
+};
+
 // A normal square root
 defineFunction("\\sqrt", {
     numArgs: 1,
@@ -114,26 +126,27 @@ defineFunction("\\sqrt", {
     };
 });
 
-// Some non-mathy text
+// Non-mathy text, possibly in a font
-defineFunction("\\text", {
+var textFunctionStyles = {
+    "\\text": undefined, "\\textrm": "mathrm", "\\textsf": "mathsf",
+    "\\texttt": "mathtt", "\\textnormal": "mathrm", "\\textbf": "mathbf",
+    "\\textit": "textit",
+};
+
+defineFunction([
+    "\\text", "\\textrm", "\\textsf", "\\texttt", "\\textnormal",
+    "\\textbf", "\\textit",
+], {
     numArgs: 1,
     argTypes: ["text"],
     greediness: 2,
+    allowedInText: true,
 }, function(context, args) {
     var body = args[0];
-    // Since the corresponding buildHTML/buildMathML function expects a
-    // list of elements, we normalize for different kinds of arguments
-    // TODO(emily): maybe this should be done somewhere else
-    var inner;
-    if (body.type === "ordgroup") {
-        inner = body.value;
-    } else {
-        inner = [body];
-    }
-
     return {
         type: "text",
-        body: inner,
+        body: ordargument(body),
+        style: textFunctionStyles[context.funcName],
     };
 });
 
@@ -146,18 +159,10 @@ defineFunction("\\color", {
 }, function(context, args) {
     var color = args[0];
     var body = args[1];
-    // Normalize the different kinds of bodies (see \text above)
-    var inner;
-    if (body.type === "ordgroup") {
-        inner = body.value;
-    } else {
-        inner = [body];
-    }
-
     return {
         type: "color",
         color: color.value,
-        value: inner,
+        value: ordargument(body),
     };
 });
 
@@ -223,37 +228,73 @@ defineFunction("\\phantom", {
     numArgs: 1,
 }, function(context, args) {
     var body = args[0];
-    var inner;
-    if (body.type === "ordgroup") {
-        inner = body.value;
-    } else {
-        inner = [body];
-    }
-
     return {
         type: "phantom",
-        value: inner,
+        value: ordargument(body),
+    };
+});
+
+// Math class commands except \mathop
+defineFunction([
+    "\\mathord", "\\mathbin", "\\mathrel", "\\mathopen",
+    "\\mathclose", "\\mathpunct", "\\mathinner",
+], {
+    numArgs: 1,
+}, function(context, args) {
+    var body = args[0];
+    return {
+        type: "mclass",
+        mclass: "m" + context.funcName.substr(5),
+        value: ordargument(body),
+    };
+});
+
+// Build a relation by placing one symbol on top of another
+defineFunction("\\stackrel", {
+    numArgs: 2,
+}, function(context, args) {
+    var top = args[0];
+    var bottom = args[1];
+
+    var bottomop = new ParseNode("op", {
+        type: "op",
+        limits: true,
+        alwaysHandleSupSub: true,
+        symbol: false,
+        value: ordargument(bottom),
+    }, bottom.mode);
+
+    var supsub = new ParseNode("supsub", {
+        base: bottomop,
+        sup: top,
+        sub: null,
+    }, top.mode);
+
+    return {
+        type: "mclass",
+        mclass: "mrel",
+        value: [supsub],
     };
 });
 
 // Extra data needed for the delimiter handler down below
 var delimiterSizes = {
-    "\\bigl" : {type: "open",    size: 1},
+    "\\bigl" : {mclass: "mopen",    size: 1},
-    "\\Bigl" : {type: "open",    size: 2},
+    "\\Bigl" : {mclass: "mopen",    size: 2},
-    "\\biggl": {type: "open",    size: 3},
+    "\\biggl": {mclass: "mopen",    size: 3},
-    "\\Biggl": {type: "open",    size: 4},
+    "\\Biggl": {mclass: "mopen",    size: 4},
-    "\\bigr" : {type: "close",   size: 1},
+    "\\bigr" : {mclass: "mclose",   size: 1},
-    "\\Bigr" : {type: "close",   size: 2},
+    "\\Bigr" : {mclass: "mclose",   size: 2},
-    "\\biggr": {type: "close",   size: 3},
+    "\\biggr": {mclass: "mclose",   size: 3},
-    "\\Biggr": {type: "close",   size: 4},
+    "\\Biggr": {mclass: "mclose",   size: 4},
-    "\\bigm" : {type: "rel",     size: 1},
+    "\\bigm" : {mclass: "mrel",     size: 1},
-    "\\Bigm" : {type: "rel",     size: 2},
+    "\\Bigm" : {mclass: "mrel",     size: 2},
-    "\\biggm": {type: "rel",     size: 3},
+    "\\biggm": {mclass: "mrel",     size: 3},
-    "\\Biggm": {type: "rel",     size: 4},
+    "\\Biggm": {mclass: "mrel",     size: 4},
-    "\\big"  : {type: "textord", size: 1},
+    "\\big"  : {mclass: "mord",     size: 1},
-    "\\Big"  : {type: "textord", size: 2},
+    "\\Big"  : {mclass: "mord",     size: 2},
-    "\\bigg" : {type: "textord", size: 3},
+    "\\bigg" : {mclass: "mord",     size: 3},
-    "\\Bigg" : {type: "textord", size: 4},
+    "\\Bigg" : {mclass: "mord",     size: 4},
 };
 
 var delimiters = [
@@ -298,17 +339,10 @@ defineFunction([
     greediness: 3,
 }, function(context, args) {
     var body = args[0];
-    var atoms;
-    if (body.type === "ordgroup") {
-        atoms = body.value;
-    } else {
-        atoms = [body];
-    }
-
     return {
         type: "color",
         color: "katex-" + context.funcName.slice(1),
-        value: atoms,
+        value: ordargument(body),
     };
 });
 
@@ -378,10 +412,24 @@ defineFunction([
     };
 });
 
+// \mathop class command
+defineFunction("\\mathop", {
+    numArgs: 1,
+}, function(context, args) {
+    var body = args[0];
+    return {
+        type: "op",
+        limits: false,
+        symbol: false,
+        value: ordargument(body),
+    };
+});
+
 // Fractions
 defineFunction([
     "\\dfrac", "\\frac", "\\tfrac",
     "\\dbinom", "\\binom", "\\tbinom",
+    "\\\\atopfrac", // can’t be entered directly
 ], {
     numArgs: 2,
     greediness: 2,
@@ -399,6 +447,9 @@ defineFunction([
         case "\\tfrac":
             hasBarLine = true;
             break;
+        case "\\\\atopfrac":
+            hasBarLine = false;
+            break;
         case "\\dbinom":
         case "\\binom":
         case "\\tbinom":
@@ -472,7 +523,7 @@ defineFunction([
         return {
             type: "delimsizing",
             size: delimiterSizes[context.funcName].size,
-            delimType: delimiterSizes[context.funcName].type,
+            mclass: delimiterSizes[context.funcName].mclass,
             value: delim.value,
         };
     }
@@ -535,7 +586,7 @@ defineFunction([
 });
 
 // Infix generalized fractions
-defineFunction(["\\over", "\\choose"], {
+defineFunction(["\\over", "\\choose", "\\atop"], {
     numArgs: 0,
     infix: true,
 }, function(context) {
@@ -547,6 +598,9 @@ defineFunction(["\\over", "\\choose"], {
         case "\\choose":
             replaceWith = "\\binom";
             break;
+        case "\\atop":
+            replaceWith = "\\\\atopfrac";
+            break;
         default:
             throw new Error("Unrecognized infix genfrac command");
     }

src/symbols.js

@@ -87,7 +87,9 @@ defineSymbol(math, main, punct, "\u22c5", "\\cdotp");
 
 // Misc Symbols
 defineSymbol(math, main, textord, "\u0023", "\\#");
+defineSymbol(text, main, textord, "\u0023", "\\#");
 defineSymbol(math, main, textord, "\u0026", "\\&");
+defineSymbol(text, main, textord, "\u0026", "\\&");
 defineSymbol(math, main, textord, "\u2135", "\\aleph");
 defineSymbol(math, main, textord, "\u2200", "\\forall");
 defineSymbol(math, main, textord, "\u210f", "\\hbar");
@@ -394,8 +396,11 @@ defineSymbol(math, ams, rel, "\u21be", "\\restriction");
 
 defineSymbol(math, main, textord, "\u2018", "`");
 defineSymbol(math, main, textord, "$", "\\$");
+defineSymbol(text, main, textord, "$", "\\$");
 defineSymbol(math, main, textord, "%", "\\%");
+defineSymbol(text, main, textord, "%", "\\%");
 defineSymbol(math, main, textord, "_", "\\_");
+defineSymbol(text, main, textord, "_", "\\_");
 defineSymbol(math, main, textord, "\u2220", "\\angle");
 defineSymbol(math, main, textord, "\u221e", "\\infty");
 defineSymbol(math, main, textord, "\u2032", "\\prime");
@@ -534,7 +539,9 @@ defineSymbol(math, main, bin, "\u22c6", "\\star");
 defineSymbol(math, main, bin, "\u25c3", "\\triangleleft");
 defineSymbol(math, main, bin, "\u25b9", "\\triangleright");
 defineSymbol(math, main, open, "{", "\\{");
+defineSymbol(text, main, textord, "{", "\\{");
 defineSymbol(math, main, close, "}", "\\}");
+defineSymbol(text, main, textord, "}", "\\}");
 defineSymbol(math, main, open, "{", "\\lbrace");
 defineSymbol(math, main, close, "}", "\\rbrace");
 defineSymbol(math, main, open, "[", "\\lbrack");
@@ -652,3 +659,11 @@ for (i = 0x0410; i <= 0x044F; i++) {
     ch = String.fromCharCode(i);
     defineSymbol(text, main, textord, ch, ch);
 }
+
+// Unicode versions of existing characters
+defineSymbol(text, main, textord, "\u2013", "–");
+defineSymbol(text, main, textord, "\u2014", "—");
+defineSymbol(text, main, textord, "\u2018", "‘");
+defineSymbol(text, main, textord, "\u2019", "’");
+defineSymbol(text, main, textord, "\u201c", "“");
+defineSymbol(text, main, textord, "\u201d", "”");

static/katex.less

@@ -49,6 +49,14 @@
         display: inline-block;
     }
 
+    .mathrm {
+        font-style: normal;
+    }
+
+    .textit {
+        font-style: italic;
+    }
+
     .mathit {
         font-family: KaTeX_Math;
         font-style: italic;

test/katex-spec.js

@@ -606,6 +606,15 @@ describe("A frac parser", function() {
         expect(tfracParse.value.numer).toBeDefined();
         expect(tfracParse.value.denom).toBeDefined();
     });
+
+    it("should parse atop", function() {
+        var parse = getParsed("x \\atop y")[0];
+
+        expect(parse.type).toEqual("genfrac");
+        expect(parse.value.numer).toBeDefined();
+        expect(parse.value.denom).toBeDefined();
+        expect(parse.value.hasBarLine).toEqual(false);
+    });
 });
 
 describe("An over parser", function() {
@@ -883,8 +892,8 @@ describe("A delimiter sizing parser", function() {
         var leftParse = getParsed(normalDelim)[0];
         var rightParse = getParsed(bigDelim)[0];
 
-        expect(leftParse.value.delimType).toEqual("open");
+        expect(leftParse.value.mclass).toEqual("mopen");
-        expect(rightParse.value.delimType).toEqual("close");
+        expect(rightParse.value.mclass).toEqual("mclose");
     });
 
     it("should parse the correct size delimiter", function() {
@@ -1373,6 +1382,43 @@ describe("An HTML font tree-builder", function() {
         expect(markup).toContain("<span class=\"mord mathfrak\">R</span>");
     });
 
+    it("should render \\text{R} with the correct font", function() {
+        var markup = katex.renderToString("\\text{R}");
+        expect(markup).toContain("<span class=\"mord mathrm\">R</span>");
+    });
+
+    it("should render \\textit{R} with the correct font", function() {
+        var markup = katex.renderToString("\\textit{R}");
+        expect(markup).toContain("<span class=\"mord textit\">R</span>");
+    });
+
+    it("should render \\text{\\textit{R}} with the correct font", function() {
+        var markup = katex.renderToString("\\text{\\textit{R}}");
+        expect(markup).toContain("<span class=\"mord textit\">R</span>");
+    });
+
+    it("should render \\text{R\\textit{S}T} with the correct fonts", function() {
+        var markup = katex.renderToString("\\text{R\\textit{S}T}");
+        expect(markup).toContain("<span class=\"mord mathrm\">R</span>");
+        expect(markup).toContain("<span class=\"mord textit\">S</span>");
+        expect(markup).toContain("<span class=\"mord mathrm\">T</span>");
+    });
+
+    it("should render \\textbf{R} with the correct font", function() {
+        var markup = katex.renderToString("\\textbf{R}");
+        expect(markup).toContain("<span class=\"mord mathbf\">R</span>");
+    });
+
+    it("should render \\textsf{R} with the correct font", function() {
+        var markup = katex.renderToString("\\textsf{R}");
+        expect(markup).toContain("<span class=\"mord mathsf\">R</span>");
+    });
+
+    it("should render \\texttt{R} with the correct font", function() {
+        var markup = katex.renderToString("\\texttt{R}");
+        expect(markup).toContain("<span class=\"mord mathtt\">R</span>");
+    });
+
     it("should render a combination of font and color changes", function() {
         var markup = katex.renderToString("\\color{blue}{\\mathbb R}");
         var span = "<span class=\"mord mathbb\" style=\"color:blue;\">R</span>";

test/screenshotter/ss_data.yaml

@@ -26,6 +26,11 @@ Arrays: |
 ArrayType: 1\begin{array}{c}2\\3\end{array}4
 Baseline: a+b-c\cdot d/e
 BasicTest: a
+BinCancellation: |
+    \begin{array}{ccc}
+        +1 & 1+ & 1+1 & (,) \\
+        1++1 & 3\times) & 1+, & \left(,\right)
+    \end{array}
 BinomTest: \dbinom{a}{b}\tbinom{a}{b}^{\binom{a}{b}+17}
 BoldSpacing: \mathbf{A}^2+\mathbf{B}_3*\mathscr{C}'
 Cases: |
@@ -57,7 +62,7 @@ DisplayStyle: |
     {\displaystyle\sqrt{x}}{\sqrt{x}}
     {\displaystyle \frac12}{\frac12}{\displaystyle x^1_2}{x^1_2}
 Exponents: a^{a^a_a}_{a^a_a}
-FractionTest: \dfrac{a}{b}\frac{a}{b}\tfrac{a}{b}\;-\dfrac12\;1\tfrac12
+FractionTest: \dfrac{a}{b}\frac{a}{b}\tfrac{a}{b}\;-\dfrac12\;1\tfrac12\;{1 \atop 2}
 Functions: \sin\cos\tan\ln\log
 GreekLetters: \alpha\beta\gamma\omega
 KaTeX: \KaTeX
@@ -74,6 +79,8 @@ LeftRightStyleSizing: |
 LimitControls: |
     \displaystyle\int\limits_2^3 3x^2\,dx + \sum\nolimits^n_{i=1}i +
     \textstyle\int\limits_x^y z
+MathAtom: a\mathrel{\mathop{=}\limits^{\blue ?}}b
+MathAtom2: \mathop{\overline\mathrm{lim}}\limits_{x\to\infty}f(x)
 MathDefaultFonts: Ax2k\breve{a}\omega\Omega\imath+\KaTeX
 MathBb: \mathbb{Ax2k\breve{a}\omega\Omega\imath+\KaTeX}
 MathBf: \mathbf{Ax2k\breve{a}\omega\Omega\imath+\KaTeX}
@@ -109,6 +116,7 @@ Sqrt: |
     ^{\sqrt{\sqrt{\sqrt{x}}}}}
 SqrtRoot: |
     1+\sqrt[3]{2}+\sqrt[1923^234]{2^{2^{2^{2^{2^{2^{2^{2^{2^{2^{2^2}}}}}}}}}}}
+StackRel: a \stackrel{?}{=} b \stackrel{\text{def}}{=} c
 StyleSwitching: a\cdot b\scriptstyle a\cdot ba\textstyle\cdot ba\scriptstyle\cdot b
 SupSubCharacterBox: a_2f_2{f}_2{aa}_2{af}_2\mathbf{y}_Ay_A
 SupSubHorizSpacing: |