Nuprl Lemma : member-fset-pair

∀[T:Type]. ∀eq:EqDecider(T). ∀x,y,z:T.  uiff(z ∈ {x,y};(z = x ∈ T) ∨ (z = y ∈ T))


Proof




Definitions occuring in Statement :  fset-pair: {a,b},  fset-member: a ∈ s,  deq: EqDecider(T),  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  or: P ∨ Q,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  implies: P ⇒ Q,  guard: {T},  fset-pair: {a,b},  fset-member: a ∈ s,  top: Top,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  prop: ℙ,  or: P ∨ Q,  iff: P ⇐⇒ Q,  assert: ↑b,  ifthenelse: if b then t else f fi ,  bfalse: ff,  rev_implies: P ⇐ Q,  eqof: eqof(d),  decidable: Dec(P),  not: ¬A,  false: False
Lemmas referenced :  deq-implies,  deq_member_cons_lemma,  deq_member_nil_lemma,  deq_wf,  or_wf,  equal_wf,  bor_wf,  eqof_wf,  bfalse_wf,  assert_wf,  false_wf,  uiff_wf,  assert_witness,  iff_transitivity,  iff_weakening_uiff,  assert_of_bor,  safe-assert-deq
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  because_Cache,  independent_functionElimination,  hypothesis,  sqequalRule,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesisEquality,  cumulativity,  universeEquality,  independent_pairFormation,  applyEquality,  addLevel,  productElimination,  rename,  independent_isectElimination,  orFunctionality,  unionElimination,  inlFormation,  inrFormation,  equalitySymmetry

Latex:
\mforall{}[T:Type].  \mforall{}eq:EqDecider(T).  \mforall{}x,y,z:T.    uiff(z  \mmember{}  \{x,y\};(z  =  x)  \mvee{}  (z  =  y))



Date html generated: 2017_04_17-AM-09_18_59
Last ObjectModification: 2017_02_27-PM-05_22_29

Theory : finite!sets


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