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: a function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a squash: T prop: implies:  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: ⇐⇒ Q cand: c∧ B rev_implies:  Q subtype_rel: A ⊆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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