constr_viol_tol:

Desired threshold for the constraint violation. $\;$
Absolute tolerance on the constraint violation. Successful termination requires that the max-norm of the (unscaled) constraint violation is less than this threshold. The valid range for this real option is $0 < {\tt constr\_viol\_tol } < {\tt +inf}$ and its default value is $0.0001$.