-lemma tpr_inv_lift: â\88\80T1,T2. T1 â\87\92 T2 →
- â\88\80d,e,U1. â\87\91[d, e] U1 ≡ T1 →
- â\88\83â\88\83U2. â\87\91[d, e] U2 â\89¡ T2 & U1 â\87\92 U2.
+lemma tpr_inv_lift: â\88\80T1,T2. T1 â\9e¡ T2 →
+ â\88\80d,e,U1. â\87§[d, e] U1 ≡ T1 →
+ â\88\83â\88\83U2. â\87§[d, e] U2 â\89¡ T2 & U1 â\9e¡ U2.