Nuprl Lemma : free-letter_wf

[X:Type]. ∀[x:X].  (free-letter(x) ∈ free-word(X))


Proof




Definitions occuring in Statement :  free-letter: free-letter(x) free-word: free-word(X) uall: [x:A]. B[x] member: t ∈ T universe: Type
Definitions unfolded in proof :  free-word: free-word(X) uall: [x:A]. B[x] member: t ∈ T free-letter: free-letter(x) subtype_rel: A ⊆B so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] uimplies: supposing a
Lemmas referenced :  cons_wf nil_wf subtype_quotient list_wf word-equiv_wf word-equiv-equiv
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin unionEquality cumulativity hypothesisEquality inlEquality hypothesis applyEquality lambdaEquality independent_isectElimination axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality because_Cache universeEquality

Latex:
\mforall{}[X:Type].  \mforall{}[x:X].    (free-letter(x)  \mmember{}  free-word(X))



Date html generated: 2020_05_20-AM-08_22_46
Last ObjectModification: 2017_01_15-PM-01_15_50

Theory : free!groups


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