Nuprl Lemma : not-not-assert

[b:𝔹]. uiff(¬¬↑b;↑b)


Proof




Definitions occuring in Statement :  assert: b bool: 𝔹 uiff: uiff(P;Q) uall: [x:A]. B[x] not: ¬A
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a implies:  Q prop: not: ¬A false: False all: x:A. B[x] decidable: Dec(P) or: P ∨ Q
Lemmas referenced :  assert_witness not_wf assert_wf false_wf bool_wf decidable__assert
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut independent_pairFormation lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality independent_functionElimination hypothesis lambdaFormation lambdaEquality voidElimination functionEquality sqequalRule dependent_functionElimination productElimination independent_pairEquality isect_memberEquality because_Cache equalityTransitivity equalitySymmetry unionElimination

Latex:
\mforall{}[b:\mBbbB{}].  uiff(\mneg{}\mneg{}\muparrow{}b;\muparrow{}b)



Date html generated: 2016_05_15-PM-03_27_14
Last ObjectModification: 2015_12_27-PM-01_08_22

Theory : general


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