Question

I am working on prolog and faced this scenario –
In my query, I pass something like this:

?- query( 2*X + 3*Y >= 3*Z )

Now, what I would like to do is have the prolog program capture the inequality expression so that I can have the above inequality in variables like below:

variable ‘Lhs‘ will have 2*X + 3*Y
variable ‘Rhs‘ will have 3*Z
Now I want the inequality involved to be also assigned somewhere (in a variable called Opr??), so that saying something like Lhs Opr Rhs would mean exactly like saying “2*X + 3*Y >= 3*Z“..

This is a general form of the scenario that I am working on. I somehow want the “inequality” involved to be identified, so that I can use it later in my code.

I am working on Eclipse-CLP with IC library.

Answer 1

You can use univ to disassemble your inequaliy:

Eq =.. [Op,Lhs,Rhs],

This works in both directions.