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: b supposing a
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
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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