-theorem lreq_join: â\88\80f1,L1,L2. L1 â\89¡[f1] L2 â\86\92 â\88\80f2. L1 â\89¡[f2] L2 →
- â\88\80f. f1 â\8b\93 f2 â\89¡ f â\86\92 L1 â\89¡[f] L2.
+theorem lreq_join: â\88\80f1,L1,L2. L1 â\89\90[f1] L2 â\86\92 â\88\80f2. L1 â\89\90[f2] L2 →
+ â\88\80f. f1 â\8b\93 f2 â\89¡ f â\86\92 L1 â\89\90[f] L2.