Nuprl Lemma : member-fset-map

∀[T:Type]. ∀[eqT:EqDecider(T)]. ∀[X:Type]. ∀[eqX:EqDecider(X)]. ∀[f:T ⟶ X]. ∀[s:fset(T)]. ∀[x:X].
  uiff(x ∈ fset-map(f;s);↓∃y:T. (y ∈ s ∧ (x = (f y) ∈ X)))


Proof




Definitions occuring in Statement :  fset-map: fset-map(f;s),  fset-member: a ∈ s,  fset: fset(T),  deq: EqDecider(T),  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  exists: ∃x:A. B[x],  squash: ↓T,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  squash: ↓T,  prop: ℙ,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  fset: fset(T),  quotient: x,y:A//B[x; y],  fset-map: fset-map(f;s),  fset-member: a ∈ s,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  cand: A c∧ B,  rev_implies: P ⇐ Q,  subtype_rel: A ⊆r B,  guard: {T},  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  false: False,  sq_type: SQType(T),  true: True
Lemmas referenced :  fset-member_wf,  fset-map_wf,  fset-member_witness,  squash_wf,  equal_wf,  fset_wf,  deq_wf,  istype-universe,  assert-deq-member,  map_wf,  member-map,  subtype_rel_self,  list_wf,  set-equal_wf,  decidable__fset-member,  set-equal-reflex,  l_member_wf,  subtype_base_sq,  int_subtype_base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  independent_pairFormation,  hypothesis,  sqequalHypSubstitution,  imageElimination,  sqequalRule,  imageMemberEquality,  hypothesisEquality,  thin,  baseClosed,  Error :universeIsType,  extract_by_obid,  isectElimination,  independent_functionElimination,  productEquality,  applyEquality,  productElimination,  independent_pairEquality,  Error :isect_memberEquality_alt,  Error :isectIsTypeImplies,  Error :inhabitedIsType,  because_Cache,  Error :functionIsType,  instantiate,  universeEquality,  pointwiseFunctionalityForEquality,  pertypeElimination,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  Error :dependent_pairFormation_alt,  Error :productIsType,  Error :equalityIstype,  sqequalBase,  unionElimination,  promote_hyp,  Error :lambdaFormation_alt,  pointwiseFunctionality,  voidElimination,  Error :equalityIsType4,  intEquality,  natural_numberEquality,  cumulativity,  independent_isectElimination

Latex:
\mforall{}[T:Type].  \mforall{}[eqT:EqDecider(T)].  \mforall{}[X:Type].  \mforall{}[eqX:EqDecider(X)].  \mforall{}[f:T  {}\mrightarrow{}  X].  \mforall{}[s:fset(T)].  \mforall{}[x:X].
    uiff(x  \mmember{}  fset-map(f;s);\mdownarrow{}\mexists{}y:T.  (y  \mmember{}  s  \mwedge{}  (x  =  (f  y))))



Date html generated: 2019_06_20-PM-01_58_53
Last ObjectModification: 2018_11_23-PM-04_42_10

Theory : finite!sets


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