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: T List,  uall: ∀[x:A]. B[x],  not: ¬A,  member: t ∈ T,  set: {x:A| B[x]} ,  product: x:A × B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  vars-of-subst: vars-of-subst(s),  prop: ℙ,  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  bfalse: ff,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b 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: P ⇐ Q,  iff: P ⇐⇒ 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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