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: ⇐⇒ Q true: True universe: Type
Definitions unfolded in proof :  all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q member: t ∈ T uall: [x:A]. B[x] rev_implies:  Q prop: so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] uimplies: 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 ⊆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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