Nuprl Lemma : fset-constrained-image-singleton

[eqt,eqa:Top]. ∀[T,A:Type]. ∀[f:T ⟶ A]. ∀[P:A ⟶ 𝔹]. ∀[x:T].  (f"({x}) s.t. if (f x) then {f x} else {} fi )


Proof




Definitions occuring in Statement :  fset-constrained-image: f"(s) s.t. P empty-fset: {} fset-singleton: {x} ifthenelse: if then else fi  bool: 𝔹 uall: [x:A]. B[x] top: Top apply: a function: x:A ⟶ B[x] universe: Type sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T fset-singleton: {x} fset-constrained-image: f"(s) s.t. P f-union: f-union(domeq;rngeq;s;x.g[x]) all: x:A. B[x] top: Top so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] fset-union: x ⋃ y l-union: as ⋃ bs implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] prop: or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False empty-fset: {}
Lemmas referenced :  list_accum_cons_lemma list_accum_nil_lemma bool_wf eqtt_to_assert reduce_cons_lemma reduce_nil_lemma insert_nil_lemma eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot top_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule extract_by_obid sqequalHypSubstitution dependent_functionElimination thin isect_memberEquality voidElimination voidEquality hypothesis applyEquality functionExtensionality hypothesisEquality cumulativity lambdaFormation unionElimination equalityElimination isectElimination equalityTransitivity equalitySymmetry productElimination independent_isectElimination dependent_pairFormation promote_hyp instantiate because_Cache independent_functionElimination sqequalAxiom functionEquality universeEquality

Latex:
\mforall{}[eqt,eqa:Top].  \mforall{}[T,A:Type].  \mforall{}[f:T  {}\mrightarrow{}  A].  \mforall{}[P:A  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[x:T].
    (f"(\{x\})  s.t.  P  \msim{}  if  P  (f  x)  then  \{f  x\}  else  \{\}  fi  )



Date html generated: 2017_04_17-AM-09_21_11
Last ObjectModification: 2017_02_27-PM-05_23_57

Theory : finite!sets


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