Nuprl Lemma : vars-of-subst_wf

[opr:Type]. ∀[s:(varname() × term(opr)) List].  (vars-of-subst(s) ∈ {v:varname()| ¬(v nullvar() ∈ varname())}  List)


Proof




Definitions occuring in Statement :  vars-of-subst: vars-of-subst(s) term: term(opr) nullvar: nullvar() varname: varname() list: List uall: [x:A]. B[x] not: ¬A member: t ∈ T set: {x:A| B[x]}  product: x:A × B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T vars-of-subst: vars-of-subst(s) prop: subtype_rel: A ⊆B all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  bfalse: ff uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False not: ¬A rev_implies:  Q iff: ⇐⇒ Q
Lemmas referenced :  l-union-list_wf varname_wf not_wf equal_wf nullvar_wf var-deq_wf map_wf term_wf list_wf eq_var_wf free-vars_wf eqff_to_assert bool_cases_sqequal subtype_base_sq bool_wf bool_subtype_base assert-bnot iff_weakening_uiff assert_wf equal-wf-T-base assert-eq_var insert_wf istype-void istype-universe
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin closedConclusion setEquality hypothesis hypothesisEquality applyEquality because_Cache productEquality lambdaEquality_alt productElimination inhabitedIsType lambdaFormation_alt unionElimination equalityElimination independent_isectElimination equalityTransitivity equalitySymmetry dependent_pairFormation_alt equalityIstype promote_hyp dependent_functionElimination instantiate cumulativity independent_functionElimination voidElimination dependent_set_memberEquality_alt functionIsType productIsType universeIsType axiomEquality isect_memberEquality_alt isectIsTypeImplies universeEquality

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



Date html generated: 2020_05_19-PM-09_57_42
Last ObjectModification: 2020_03_09-PM-04_09_56

Theory : terms


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