| validrefs(str, r ' + refs1, st[r -- _type] .type, st) ⊦ dups(refs1), refs1 = [], r = refs1 .last, ∃ refs. refs ≠ [] ∧ refs .first = r ∧ refs .last = refs1 .last ∧ ¬ dups(refs) ∧ validrefs(str, refs, st[refs .first -- _type] .type, st), ¬ r ∈ refs1 ∧ ¬ dups(refs1) |
validrefs(str, r ' + refs1, st[r -- _type] .type, st), r ∈ refs1 ⊦ refs1 = [], r = refs1 .last, dups(refs1), ∃ refs. refs ≠ [] ∧ refs .first = r ∧ refs .last = refs1 .last ∧ ¬ dups(refs) ∧ validrefs(str, refs, st[refs .first -- _type] .type, st)
[[CONCRETESIMPRULES : ()]]