Nuprl Lemma : eqff_assert_2
∀[b:Decision]. uiff(b = ff ∈ Decision;¬↑b)
Proof
Definitions occuring in Statement : 
decision: Decision
, 
assert: ↑b
, 
bfalse: ff
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
not: ¬A
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
decision: Decision
, 
assert: ↑b
, 
bfalse: ff
, 
ifthenelse: if b then t else f fi 
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
isl: isl(x)
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
top: Top
, 
true: True
Lemmas referenced : 
btrue_wf, 
bfalse_wf, 
and_wf, 
equal_wf, 
top_wf, 
isl_wf, 
btrue_neq_bfalse, 
true_wf, 
it_wf, 
unit_wf2, 
not_wf, 
false_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
unionElimination, 
thin, 
sqequalRule, 
independent_pairFormation, 
lambdaFormation, 
lemma_by_obid, 
hypothesis, 
equalitySymmetry, 
dependent_set_memberEquality, 
equalityTransitivity, 
isectElimination, 
unionEquality, 
hypothesisEquality, 
applyEquality, 
lambdaEquality, 
setElimination, 
rename, 
productElimination, 
setEquality, 
independent_functionElimination, 
voidElimination, 
dependent_functionElimination, 
inlEquality, 
inrEquality, 
isect_memberEquality, 
voidEquality, 
natural_numberEquality, 
because_Cache, 
independent_pairEquality, 
axiomEquality
Latex:
\mforall{}[b:Decision].  uiff(b  =  ff;\mneg{}\muparrow{}b)
Date html generated:
2016_05_15-PM-01_44_24
Last ObjectModification:
2015_12_27-AM-00_10_37
Theory : basic
Home
Index