evenp integer → generalized-boolean

oddp integer → generalized-boolean

integer — an integer.

generalized-boolean — a generalized boolean.

evenp returns true if integer is even (divisible by two); otherwise, returns false.

oddp returns true if integer is odd (not divisible by two); otherwise, returns false.

(evenp 0) → true 
(oddp 10000000000000000000000) → false 
(oddp -1) → true

Should signal an error of type type-error if integer is not an integer.

(evenp integer) ≡ (not (oddp integer)) 
(oddp integer)  ≡ (not (evenp integer))