Subtracting

Subtraction in LIGO is accomplished by means of the - binary operator which is overloaded to apply to any combination of natural numbers and integers, as shown in the following examples. The rule when subtracting two natural numbers is that the result is an integer because, in general, the compiler cannot determine whether the value of an expression is positive or zero for all inputs.

const a : int = 5 - 10; // int - int yields int

const b : int = 5n - 2n; // nat - nat yields int

const c : int = 10n - 5; // nat - int yields int

const d : int = 5 - 10n; // int - nat yields int

// const error : nat = 5n - 2n;