The Equality module tests whether its two inputs are equal to one another within a given Tolerance.
Or in Capytalk, you could create a logical AND by multiplying two tests, for example:
((1 ramp) le: (!Value + !Tolerance)) * ((1 ramp) ge: (!Value - !Tolerance))
Basically, that would test when the ramp is equal to !Value but it's relaxing the condition by widening the range of acceptable values by (2 * !Tolerance).
Would either of these get you close to what you're looking for?