PPT Slide

EQUAL is the most general equality test in Lisp

( equal x y ) returns

T if ( EQL x y ) or

if x and y are S-expressions whose components are equal.

NIL otherwise.

( equal ’( a b ) ’( a b ) ) T

( equal ’( a b ) ( list ’a ’b ) ) T

( equal ’( a b ) (cons ’a (cons ’b NIL) ) ) T