ocr: 11 - Unifi ication Page 7 When two structures uith variables are unified with each other, the variables take on values which make the two structures the same. Mote that a structure bound to a variable can itself contain variables. 77- X = a(b,c). X : = a(b, c) -> yes 77- - a(b,X) = a(b,c(d,e)). X = cld, e) -> yes 77- alb,X) = a(b,c(Y,e)). x = C(_2F3D, e) Y =. 2F3D-> Legal Keys: : (ask for nore) 1- (accept ansuer) Figure 1. One frame OfAPT's unification chapter
