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Boolean and Logical

FunctionSyntaxDescription
not(not expr)Logical NOT
and(and e1 e2 ...)Logical AND (all evaluated)
or(or e1 e2 ...)Logical OR (all evaluated)
andalso(andalso e1 e2 ...)Short-circuit AND
orelse(orelse e1 e2 ...)Short-circuit OR
xor(xor e1 e2)Logical XOR

Short-Circuit Evaluation:

;; andalso stops at first false
(andalso (< x 10) (expensive-check x))

;; orelse stops at first true
(orelse (is-cached x) (compute-expensive x))

;; Regular and/or evaluate all arguments
(and (< x 10) (expensive-check x))  ; Always calls expensive-check