Nuprl Lemma : free-vars_wf

[opr:Type]. ∀[t:term(opr)].  (free-vars(t) ∈ {v:varname()| ¬(v nullvar() ∈ varname())}  List)


Proof




Definitions occuring in Statement :  free-vars: free-vars(t) term: term(opr) nullvar: nullvar() varname: varname() list: List uall: [x:A]. B[x] not: ¬A member: t ∈ T set: {x:A| B[x]}  universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T free-vars: free-vars(t)
Lemmas referenced :  free-vars-aux_wf nil_wf varname_wf term_wf istype-universe
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis axiomEquality equalityTransitivity equalitySymmetry universeIsType isect_memberEquality_alt isectIsTypeImplies inhabitedIsType instantiate universeEquality

Latex:
\mforall{}[opr:Type].  \mforall{}[t:term(opr)].    (free-vars(t)  \mmember{}  \{v:varname()|  \mneg{}(v  =  nullvar())\}    List)



Date html generated: 2020_05_19-PM-09_56_09
Last ObjectModification: 2020_03_09-PM-04_09_14

Theory : terms


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