Abstract :
Syntactic clues are aids to parsing. The amount of nondeterminism in parsers for pairs of homomorphically related semithue language systems is compared. If the parsers are without lookahead, the domain language system parser has no more nondeterminism than the codomain language system parser. The domain language system has at least as many clues. If the parsers have lookahead and the homomorphism is nondecreasing the same results hold. If the homomorphism is nonincreasing, an example shows the codomain language system may have the better clues.
