Nuprl Lemma : opt_wf
∀[T:Type]. ∀[x:T]. ∀[b:𝔹].  ((b?x) ∈ T?)
Proof
Definitions occuring in Statement : 
opt: (b?x), 
bool: 𝔹, 
uall: ∀[x:A]. B[x], 
unit: Unit, 
member: t ∈ T, 
union: left + right, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
opt: (b?x), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
exposed-bfalse: exposed-bfalse, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
prop: ℙ
Lemmas referenced : 
eqtt_to_assert, 
unit_wf2, 
uiff_transitivity, 
equal-wf-T-base, 
bool_wf, 
assert_wf, 
bnot_wf, 
not_wf, 
eqff_to_assert, 
assert_of_bnot, 
it_wf, 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
hypothesisEquality, 
thin, 
because_Cache, 
lambdaFormation, 
sqequalHypSubstitution, 
unionElimination, 
equalityElimination, 
extract_by_obid, 
isectElimination, 
hypothesis, 
productElimination, 
independent_isectElimination, 
inlEquality, 
baseClosed, 
independent_functionElimination, 
inrEquality, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
axiomEquality, 
universeIsType, 
isect_memberEquality, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}[x:T].  \mforall{}[b:\mBbbB{}].    ((b?x)  \mmember{}  T?)
Date html generated:
2019_10_15-AM-10_46_43
Last ObjectModification:
2018_09_27-AM-09_37_27
Theory : basic
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