| ∀ str, ty, st, refs1. validrefs(str, refs0, ty, st) ∧ junkrefs(str, refs0 .last ' + refs1, st[refs0 .last -- _type] .type, st) → refs0 = [] ∨ junkrefs(str, refs0 + refs1, ty, st), validrefs(str, r + refs0, ty, st), junkrefs(str, (r + refs0) .last ' + refs1, st[(r + refs0) .last -- _type] .type, st) ⊦ r + refs0 = [], junkrefs(str, (r + refs0) + refs1, ty, st) |
validrefs(str, r ' + refs0, ty, st), junkrefs(str, (r ' + refs0) .last ' + refs1, st[(r ' + refs0) .last -- _type] .type, st), ∀ str, ty, st, refs1. validrefs(str, refs0, ty, st) ∧ junkrefs(str, refs0 .last ' + refs1, st[refs0 .last -- _type] .type, st) → refs0 = [] ∨ junkrefs(str, refs0 + refs1, ty, st) ⊦ junkrefs(str, (r ' + refs0) + refs1, ty, st)
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ (refs + refs0) + refs1 = refs + refs0 + refs1], [CSIMPSEQ : ⊦ r ' + refs ≠ []], [CSIMPSEQ : ⊦ r + refs = r ' + refs])]]