Nuprl Lemma : fset-pair-symmetry

∀[T:Type]. ∀[a,b:T].  ({a,b} = {b,a} ∈ fset(T))


Proof




Definitions occuring in Statement :  fset-pair: {a,b},  fset: fset(T),  uall: ∀[x:A]. B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  rev_implies: P ⇐ Q,  false: False,  prop: ℙ,  guard: {T},  or: P ∨ Q,  and: P ∧ Q,  iff: P ⇐⇒ Q,  set-equal: set-equal(T;x;y),  implies: P ⇒ Q,  all: ∀x:A. B[x],  uimplies: b supposing a,  so_apply: x[s1;s2],  so_lambda: λ2x y.t[x; y],  fset: fset(T),  member: t ∈ T,  uall: ∀[x:A]. B[x],  fset-pair: {a,b}
Lemmas referenced :  iff_wf,  l_member_wf,  nil_member,  cons_member,  or_wf,  equal_wf,  false_wf,  nil_wf,  cons_wf,  set-equal-equiv,  list_wf,  set-equal_wf,  quotient-member-eq
Rules used in proof :  orFunctionality,  productElimination,  addLevel,  voidElimination,  inlFormation,  inrFormation,  unionElimination,  independent_pairFormation,  lambdaFormation,  axiomEquality,  isect_memberEquality,  independent_functionElimination,  dependent_functionElimination,  independent_isectElimination,  hypothesis,  hypothesisEquality,  cumulativity,  lambdaEquality,  because_Cache,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  cut,  introduction,  isect_memberFormation,  computationStep,  sqequalTransitivity,  sqequalReflexivity,  sqequalRule,  sqequalSubstitution

Latex:
\mforall{}[T:Type].  \mforall{}[a,b:T].    (\{a,b\}  =  \{b,a\})



Date html generated: 2017_02_20-AM-10_48_42
Last ObjectModification: 2017_02_10-PM-02_29_32

Theory : finite!sets


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