The UNTIL statement has the form
UNTIL logical-expression,sequence
where sequence is one or more executable statements enclosed by statement brackets.
Its action is to cause the statements within sequence to be continuously executed until logical-expresssion acquires the value of true (_T).
The value of the expression upon entry into the UNTIL statement is ignored.
@-commented as WHILE. In addition, if the logical expression is a test for equality, @BECOMES= instead of @EQUALS= is recommended. (&'...' substitutes exist for separators, not for operators, so the equals sign cannot be replaced in this way.)
If the sequence argument is omitted, the statement must be numbered, and causes a REPEAT statement referring to that number to branch to the statement following the UNTIL statement if logical-expression has the value false. In this case, the reaction to an initially true logical expression is the same in both forms of the statement.