Nuprl Lemma : quotient-squash

[T:Type]. ∀[E:T ⟶ T ⟶ ℙ].  x,y:T//E[x;y] ≡ x,y:T//(↓E[x;y]) supposing EquivRel(T;x,y.E[x;y])


Proof




Definitions occuring in Statement :  equiv_rel: EquivRel(T;x,y.E[x; y]) quotient: x,y:A//B[x; y] ext-eq: A ≡ B uimplies: supposing a uall: [x:A]. B[x] prop: so_apply: x[s1;s2] squash: T function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] implies:  Q ext-eq: A ≡ B and: P ∧ Q subtype_rel: A ⊆B quotient: x,y:A//B[x; y] all: x:A. B[x] squash: T prop:
Lemmas referenced :  equiv_rel_wf equal-wf-base quotient-member-eq squash_wf quotient_wf equiv_rel_squash
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality sqequalRule lambdaEquality applyEquality independent_functionElimination hypothesis independent_pairFormation pointwiseFunctionalityForEquality independent_isectElimination pertypeElimination productElimination because_Cache dependent_functionElimination equalityTransitivity equalitySymmetry imageMemberEquality baseClosed productEquality universeEquality imageElimination independent_pairEquality axiomEquality isect_memberEquality functionEquality cumulativity

Latex:
\mforall{}[T:Type].  \mforall{}[E:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].    x,y:T//E[x;y]  \mequiv{}  x,y:T//(\mdownarrow{}E[x;y])  supposing  EquivRel(T;x,y.E[x;y])



Date html generated: 2016_05_14-AM-06_08_07
Last ObjectModification: 2016_01_14-PM-07_33_19

Theory : quot_1


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