Rbase 6.5+ DOS - Setting up rules - verify a value

[Bill Niehaus]

I have two tables called MAT and SEED.  I want to restrict data entry to the table 
SEED such that a value for column ID must exist in table MAT before allowing entry 
into SEED.

I went through the menu system for database, modify, rules, verify a value and get to 
a screen asking for Rule table, Rule column, Verification table and Verification 
column.

I have been unable to get this option to work.

What is the proper way to set up a rule to verify a value.

Thanks.   Bill Niehaus