The UNTIL statement has the form
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.