-fact crx_inv_ib2_aux: ∀h,g,a,I,L,W,U,T. ib2 a I → ⦃h, L⦄ ⊢ 𝐑[g]⦃T⦄ →
- T = ⓑ{a,I}W.U → ⦃h, L⦄ ⊢ 𝐑[g]⦃W⦄ ∨ ⦃h, L.ⓑ{I}W⦄ ⊢ 𝐑[g]⦃U⦄.
+fact crx_inv_ib2_aux: ∀h,g,a,I,L,W,U,T. ib2 a I → ⦃G, L⦄ ⊢ 𝐑[h, g]⦃T⦄ →
+ T = ⓑ{a,I}W.U → ⦃G, L⦄ ⊢ 𝐑[h, g]⦃W⦄ ∨ ⦃h, L.ⓑ{I}W⦄ ⊢ 𝐑[h, g]⦃U⦄.