Semantic Directed Translation Of Context Free Languages

A formal d e f i n i t i o n f o r t h e semantics of a c o n t e x t free language, c a l l e d a phrase-structure semantics., i s given. The d e f i n i t i o n i s a model of t h e n o t i o n t h a t i t i s phrases which have meaning and t h a t t h e meaning of a phrase is a f u n c t i o n of i t s s y n t a c t i c s t r u c t u r e and of the meanings of i t s c o n s t i t u e n t s. Next w e give a d e f i n i t i m f o r t r a n s l a t i o n on context f r e e languages. W e then study a c e r t a i n kind of t r a n s l a t i o n on cf 1's. which proceeds by t r a n s l a t i n g on t h e phrase t r e e s of t h e languages, and is s p e c i f i e d by a f i n i t e set of tree-replacement r u l e s. W e p r e s e n t a procedure which, given a cfg and p h r a s e-s t r u c t u r e semantics f o r a source language and a cfg and phrase-structure semantics f o r a t a r g e t language, w i l l (u s u a l l y) produce t h e f i n i t e set of ttee-replacement rules for tne t r a n s l a t i o n , i f the t r a n s l a t i o n e x i s t s. The procedure may be viewed as a computer program which i s a t r a n s l a t o r generator, and …