Simpler Version with the Same Problem

(defmacro if-n-z-p-alt2 (expr f1 f2 f3)

`(let ((x ,expr))

(cond ((minusp x) ,f1)

((zerop x) ,f2)

((plusp x) ,f3) ) ) )

Even though a new binding of X is created when the macro expansion is executed, any use of X in f1, f2, or f3 will end up referencing this binding rather than the global binding (variable capture).

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