A lax monoidal functor is a functor F : C ⥤ D between monoidal categories, equipped with morphisms ε : 𝟙 _D ⟶ F.obj (𝟙_ C) and μ X Y : F.obj X ⊗ F.obj Y ⟶ F.obj (X ⊗ Y), satisfying the the appropriate coherences.
A monoidal functor is a lax monoidal functor for which the tensorator and unitor as isomorphisms.
The tensorator as a natural isomorphism.
The identity monoidal functor.
The composition of two lax monoidal functors is again lax monoidal.
The composition of two monoidal functors is again monoidal.