Expression is too complex to evaluate.

    Error: The expression is too complex for the assembler to
    evaluate.

    User Action: Try grouping the expression components using angle
    brackets (< >). The most complex expression form handled by
    the assembler resolves to the form: <psect/symbol +/- offset>
    OPERATOR <psect/symbol +/- offset>, where OPERATOR is one of: +,
    -, *, /, @, \, &, or !. See Chapter 2 in the Reference Manual for
    further descriptions of the assembler evaluation of expressions.