Error 420 - Relational operator expected

Relational operator expected - The compiler has found a string operand in a position where a numeric operand should be, or a type mismatch has been detected.

For example, the statement X& = Y$ triggers an error because a string cannot be assigned or compared to numeric variable, hence the compiler expected to find an additional operator that would return a numeric result.  For example, X& = Y$ > Z$.