6.8.7.2 Iterating with the until syntax

Syntax: until ?test ?body ...

Auxiliary Syntax: continue

Auxiliary Syntax: break

If the expression ?test evaluates to false: evaluate the body forms ?body and recurse; else return unspecified values. In the body: the syntax continue causes immediate looping to next iteration, starting with the ?test; the syntax break causes immediate escaping out of the loop.