VALID returns a BIT(1) value that is '1'B under the following
conditions:
- If x is PICTURE and its contents are valid for x's picture specification
- If x is FIXED DECIMAL and the data in x is valid fixed decimal data
If these conditions are not met, the result is '0'B.
>>-VALID(x)----------------------------------------------------><
- x
- Reference with either picture or fixed decimal type.