Here is the
definition of app again with certain parts highlighted. If you are
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ACL2 !>(defun app (x y)
(cond ((endp x) y)
(t (cons (car x)
(app (cdr x) y)))))
The admission of APP is trivial, using the
relation O< (which is known to be well-founded on
the domain recognized by O-P ) and the measure
(ACL2-COUNT X). We observe that the
type of APP is described by the theorem (OR
(CONSP (APP X Y)) (EQUAL (APP X Y) Y)). We used primitive type
reasoning.
Summary
Form: ( DEFUN APP ...)
Rules: ((:FAKE-RUNE-FOR-TYPE-SET NIL))
Warnings: None
Time: 0.03 seconds (prove: 0.00, print: 0.00, other: 0.03)
APP
