real-zero -- r7rs Type number-zero;number-not-inf-not-nan;number-not-inf;number;number-not-nan;number-positive-or-zero-not-inf;number-positive-or-zero;number-negative-or-zero-not-inf;number-negative-or-zero;complex-not-inf-not-nan;complex-not-inf;complex;complex-not-nan;real-not-inf;real;real-not-nan;real-positive-or-zero;real-negative-or-zero;number?;integer?;real?;rational?;complex?;exact?;inexact?;exact-integer?;zero?;=;+;-;*;/;expt;square;inexact;sqrt;exp;log;sin;cos;tan;asin;acos;atan;number->string;<;<=;>=;>;floor/;floor-quotient;floor-remainder;truncate/;truncate-quotient;truncate-remainder;min;max;exact;finite?;infinite?;nan?;real-part;imag-part;magnitude;angle;floor;ceiling;truncate;round;rationalize;Note: These definitions consume an input that is a super-type.
Note: These definitions produce an output that is a sub-type.
(lambda (value) (and (real? value) (zero? value)))