Nuprl Lemma : choice-iff-canonicalizable
∀T:Type. (ChoicePrinciple(T) 
⇐⇒ ⇃(canonicalizable(T)))
Proof
Definitions occuring in Statement : 
choice-principle: ChoicePrinciple(T)
, 
quotient: x,y:A//B[x; y]
, 
canonicalizable: canonicalizable(T)
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
true: True
, 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
rev_implies: P 
⇐ Q
, 
prop: ℙ
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
choice-principle: ChoicePrinciple(T)
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
true: True
, 
guard: {T}
, 
pi1: fst(t)
, 
canonicalizable: canonicalizable(T)
, 
squash: ↓T
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
choice-principle_wf, 
quotient_wf, 
canonicalizable_wf, 
true_wf, 
equiv_rel_true, 
istype-universe, 
exists_wf, 
base_wf, 
equal-wf-T-base, 
istype-base, 
quotient-member-eq, 
equal-wf-base, 
implies-quotient-true2, 
all_wf, 
trivial-quotient-true, 
equal_wf, 
squash_wf, 
subtype_rel_self, 
iff_weakening_equal, 
all-quotient-true
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
independent_pairFormation, 
Error :universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
sqequalRule, 
Error :lambdaEquality_alt, 
Error :inhabitedIsType, 
because_Cache, 
independent_isectElimination, 
instantiate, 
universeEquality, 
dependent_functionElimination, 
closedConclusion, 
productElimination, 
independent_functionElimination, 
pointwiseFunctionalityForEquality, 
Error :productIsType, 
Error :equalityIsType3, 
Error :equalityIsType4, 
equalityTransitivity, 
equalitySymmetry, 
Error :dependent_pairEquality_alt, 
axiomEquality, 
natural_numberEquality, 
Error :functionIsType, 
promote_hyp, 
applyEquality, 
rename, 
Error :dependent_pairFormation_alt, 
functionExtensionality, 
Error :equalityIsType1, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
Error :equalityIsType2
Latex:
\mforall{}T:Type.  (ChoicePrinciple(T)  \mLeftarrow{}{}\mRightarrow{}  \00D9(canonicalizable(T)))
Date html generated:
2019_06_20-PM-02_54_40
Last ObjectModification:
2018_10_17-AM-09_27_27
Theory : continuity
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