 be propagated; that is, if an expression returns an error, that error would be passed, as a value, to outer expressions. For example, if the evaluator were evaluating &quot;SUM(1, (PROD(1, 2, &quot;F. T. Poomm&quot;))&quot;, PROD would return PSEE_WRONG_TYPE, since it expects numeric arguments. SUM, in turn, would be passed two arguments: the number 1 and the error PSEE_WRONG_TYPE. That function might, in turn, propagate the error upward, return a different error, or return a non-error value. (SUM, as it h