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: t ∈ T
Definitions unfolded in proof :  rev_implies:  Q false: False prop: guard: {T} or: P ∨ Q and: P ∧ Q iff: ⇐⇒ Q set-equal: set-equal(T;x;y) implies:  Q all: x:A. B[x] uimplies: supposing a so_apply: x[s1;s2] so_lambda: λ2y.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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