English
Analogous to mkQ for the right tensor, there is a correspondence between the kernel of rTensor Q N.mkQ and the image of rTensor Q N.subtype.
Русский
Аналогично для правого тензора определения ядра и образа через N-subtype.
LaTeX
$$ker( rTensor Q N.mkQ ) = range( rTensor Q N.subtype )$$
Lean4
/-- The direct map in `rTensor.equiv` -/
noncomputable def toFun (hfg : Exact f g) : N ⊗[R] Q ⧸ range (rTensor Q f) →ₗ[R] P ⊗[R] Q :=
Submodule.liftQ _ (rTensor Q g) <| by
rw [range_le_iff_comap, ← ker_comp, ← rTensor_comp, hfg.linearMap_comp_eq_zero, rTensor_zero, ker_zero]