E-TE0504 — Invalid comparison operator for a constraint

Error Type

Type Error

Phase

building constraints

Python exception

jijmodeling.ModelingError (or jijmodeling.TypeError when the invalid comparison appears in a comparison-function constraint, e.g. problem.Constraint("c", lambda i: x[i] < 3, domain=...))

Message

Invalid comparison for a constraint: expected one of `<=`, `>=`, or `==`, but got `{...}`

Cause

A constraint uses a comparison operator other than <=, >=, or == — most commonly a strict inequality < or >, or !=.

Fix

Rewrite the constraint using a non-strict inequality or equality:

problem.Constraint("c", x <= 3)   # OK
problem.Constraint("c", x < 3)    # error: strict inequality