Nuprl Lemma : sqequal-ff-to-assert
∀[t:𝔹]. uiff(t ~ ff;¬↑t)
Proof
Definitions occuring in Statement : 
assert: ↑b, 
bfalse: ff, 
bool: 𝔹, 
uiff: uiff(P;Q), 
uall: ∀[x:A]. B[x], 
not: ¬A, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
not: ¬A, 
implies: P ⇒ Q, 
false: False, 
assert: ↑b, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
prop: ℙ, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
sq_type: SQType(T), 
all: ∀x:A. B[x], 
guard: {T}
Lemmas referenced : 
false_wf, 
assert_wf, 
bool_sq, 
subtype_base_sq, 
bool_subtype_base, 
iff_imp_equal_bool, 
bfalse_wf, 
not_wf, 
bool_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
lambdaFormation, 
thin, 
hypothesis, 
sqequalRule, 
sqequalHypSubstitution, 
voidElimination, 
lemma_by_obid, 
independent_functionElimination, 
isectElimination, 
hypothesisEquality, 
lambdaEquality, 
dependent_functionElimination, 
because_Cache, 
sqequalIntensionalEquality, 
instantiate, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
sqequalAxiom, 
productElimination, 
independent_pairEquality, 
isect_memberEquality
Latex:
\mforall{}[t:\mBbbB{}].  uiff(t  \msim{}  ff;\mneg{}\muparrow{}t)
Date html generated:
2016_05_15-PM-03_14_32
Last ObjectModification:
2015_12_27-PM-01_02_16
Theory : general
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