-lemma minuss_inv_cons1: â\88\80cs1,cs2,l,m,i. {l, m} @ cs1 â\96 i â\89¡ cs2 →
- l â\89¤ i â\88§ cs1 â\96 m + i â\89¡ cs2 ∨
- â\88\83â\88\83cs. i < l & cs1 â\96 i â\89¡ cs &
+lemma minuss_inv_cons1: â\88\80cs1,cs2,l,m,i. {l, m} @ cs1 â\96 i â\89\98 cs2 →
+ l â\89¤ i â\88§ cs1 â\96 m + i â\89\98 cs2 ∨
+ â\88\83â\88\83cs. i < l & cs1 â\96 i â\89\98 cs &