Documentation for sub is-approx-calculate assembled from the following types:

module Test

From Test

(Test) sub is-approx-calculate

Defined as:

sub is-approx-calculate($got, $expected, $abs-tol where { !.defined or $_ >= 0 },
                        $rel-tol where { !.defined or $_ >= 0 }, $desc)

This is the actual routine called by is-approx when absolute and relative tolerance are specified. They are tested independently, and the test succeeds only if both pass.