rational-negative-or-zero -- r7rs Type number-negative-or-zero-not-inf;number-negative-or-zero;number-not-nan;number;number-not-inf;real-negative-or-zero;real-not-nan;complex-not-nan;complex;real;real-not-inf;complex-not-inf;real-not-inf-not-nan;complex-not-inf-not-nan;number-not-inf-not-nan;integer-zero;exact-integer-zero;integer-negative;exact-integer-negative;exact-integer-negative-or-zero;range-length-zero;(lambda (value) (and (rational? value) (or (negative? value) (zero? value))))