Nuprl Lemma : quotient-dep-function-subtype

[X:Type]
  ∀[A:X ⟶ Type]. ∀[E:x:X ⟶ A[x] ⟶ A[x] ⟶ ℙ].
    ((∀x:X. EquivRel(A[x];a,b.E[x;a;b]))
     ((x:X ⟶ (a,b:A[x]//E[x;a;b])) ⊆(f,g:x:X ⟶ A[x]//(∀x:X. (↓E[x;f x;g x]))))) 
  supposing X ⊆Base


Proof




Definitions occuring in Statement :  equiv_rel: EquivRel(T;x,y.E[x; y]) quotient: x,y:A//B[x; y] uimplies: supposing a subtype_rel: A ⊆B uall: [x:A]. B[x] prop: so_apply: x[s1;s2;s3] so_apply: x[s] all: x:A. B[x] squash: T implies:  Q apply: a function: x:A ⟶ B[x] base: Base universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a implies:  Q all: x:A. B[x] so_apply: x[s] so_lambda: λ2y.t[x; y] so_apply: x[s1;s2;s3] so_apply: x[s1;s2] prop: subtype_rel: A ⊆B equiv_rel: EquivRel(T;x,y.E[x; y]) and: P ∧ Q refl: Refl(T;x,y.E[x; y]) squash: T cand: c∧ B sym: Sym(T;x,y.E[x; y]) trans: Trans(T;x,y.E[x; y]) guard: {T} bfalse: ff ext-eq: A ≡ B ifthenelse: if then else fi  btrue: tt it: unit: Unit bool: 𝔹 isect2: T1 ⋂ T2 so_lambda: λ2x.t[x] true: True quotient: x,y:A//B[x; y]
Lemmas referenced :  quotient-squash equiv_rel_squash equiv_rel_wf subtype_rel_wf base_wf istype-universe squash_wf quotient_wf subtype_rel_weakening isect2_wf subtype_rel_transitivity isect2_subtype_rel quotient-isect-base void_wf all_wf quotient-member-eq member_wf true_wf subtype_rel_self
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  introduction cut Error :lambdaFormation_alt,  extract_by_obid sqequalHypSubstitution isectElimination thin applyEquality hypothesisEquality sqequalRule Error :lambdaEquality_alt,  Error :inhabitedIsType,  Error :universeIsType,  because_Cache independent_isectElimination hypothesis dependent_functionElimination independent_functionElimination Error :functionIsType,  axiomEquality Error :functionIsTypeImplies,  universeEquality Error :isect_memberEquality_alt,  Error :isectIsTypeImplies,  instantiate independent_pairFormation imageMemberEquality baseClosed imageElimination productElimination Error :equalityIstype,  equalityTransitivity equalitySymmetry pointwiseFunctionality closedConclusion baseApply Error :equalityIsType1,  equalityElimination unionElimination isect_memberEquality Error :functionExtensionality_alt,  voidElimination functionExtensionality functionEquality natural_numberEquality applyLambdaEquality pertypeElimination promote_hyp Error :productIsType,  sqequalBase

Latex:
\mforall{}[X:Type]
    \mforall{}[A:X  {}\mrightarrow{}  Type].  \mforall{}[E:x:X  {}\mrightarrow{}  A[x]  {}\mrightarrow{}  A[x]  {}\mrightarrow{}  \mBbbP{}].
        ((\mforall{}x:X.  EquivRel(A[x];a,b.E[x;a;b]))
        {}\mRightarrow{}  ((x:X  {}\mrightarrow{}  (a,b:A[x]//E[x;a;b]))  \msubseteq{}r  (f,g:x:X  {}\mrightarrow{}  A[x]//(\mforall{}x:X.  (\mdownarrow{}E[x;f  x;g  x]))))) 
    supposing  X  \msubseteq{}r  Base



Date html generated: 2019_06_20-PM-00_32_33
Last ObjectModification: 2018_11_26-AM-00_13_30

Theory : quot_1


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