for (let i = 0; i < this.ExpressionList.length; ++i) {
            const newExpr1 = this.ExpressionList[i].ApplySubstitution(substitution);
            const newExpr2 = otherNameExpression.ExpressionList[i].ApplySubstitution(substitution);
            const substitution2 = newExpr1.Unify(newExpr2);