13 lines
273 B
Racket
13 lines
273 B
Racket
#lang datalog/sexp
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; Equality test
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(! (:- (ancestor A B)
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(parent A B)))
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(! (:- (ancestor A B)
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(parent A C)
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(= D C) ; Unification required
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(ancestor D B)))
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(! (parent john douglas))
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(! (parent bob john))
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(! (parent ebbon bob))
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(? (ancestor A B))
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