Documentation for routine - assembled from the following pages:
Language documentation: Operators §
From Operators
(Operators) prefix - §
multi sub prefix:<->(Any --> Numeric)
Negative numeric context operator.
Coerces the argument to Numeric by calling the Numeric method on it, and then negates the result.
Language documentation: Operators §
From Operators
(Operators) infix - §
multi sub infix:<->(, --> Numeric)
Subtraction operator: Coerces both arguments to Numeric and subtracts the second from the first. From version 6.d it works also on Duration, DateTime and Real types.