Function ec_sub_unequal 

pub fn ec_sub_unequal<F: BigPrimeField, FC: FieldChip<F>>(
    chip: &FC,
    ctx: &mut Context<F>,
    P: impl Into<ComparableEcPoint<F, FC>>,
    Q: impl Into<ComparableEcPoint<F, FC>>,
    is_strict: bool,
) -> EcPoint<F, FC::FieldPoint>

If is_strict = true, then this function constrains that P.x != Q.x. If you are calling this with is_strict = false, you must ensure that P.x != Q.x by some external logic (such as a mathematical theorem).

Assumptions

• Neither P nor Q is the point at infinity (undefined behavior otherwise)