Nuprl Lemma : fset-add-remove

[T:Type]. ∀[eq:EqDecider(T)]. ∀[s:fset(T)]. ∀[x:T].  fset-add(eq;x;fset-remove(eq;x;s)) s ∈ fset(T) supposing x ∈ s


Proof




Definitions occuring in Statement :  fset-add: fset-add(eq;x;s) fset-remove: fset-remove(eq;y;s) fset-member: a ∈ s fset: fset(T) deq: EqDecider(T) uimplies: supposing a uall: [x:A]. B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a uiff: uiff(P;Q) and: P ∧ Q implies:  Q prop: or: P ∨ Q all: x:A. B[x] iff: ⇐⇒ Q rev_implies:  Q decidable: Dec(P) guard: {T} cand: c∧ B deq: EqDecider(T)
Lemmas referenced :  fset-extensionality fset-add_wf fset-remove_wf fset-member_witness or_wf equal_wf fset-member_wf not_wf member-fset-remove uiff_wf member-fset-add fset_wf deq_wf and_wf deq_property assert_wf decidable__assert decidable_functionality iff_weakening_uiff
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin because_Cache hypothesisEquality cumulativity hypothesis productElimination independent_isectElimination independent_pairFormation independent_functionElimination productEquality rename addLevel orFunctionality dependent_functionElimination sqequalRule independent_pairEquality isect_memberEquality equalityTransitivity equalitySymmetry axiomEquality universeEquality unionElimination dependent_set_memberEquality applyEquality lambdaEquality setElimination setEquality hyp_replacement Error :applyLambdaEquality,  inlFormation inrFormation

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[s:fset(T)].  \mforall{}[x:T].
    fset-add(eq;x;fset-remove(eq;x;s))  =  s  supposing  x  \mmember{}  s



Date html generated: 2016_10_21-AM-10_44_15
Last ObjectModification: 2016_07_12-AM-05_51_07

Theory : finite!sets


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