Nuprl Lemma : quotient-of-quotient

∀T:Type. ∀R:T ⟶ T ⟶ ℙ.
  (EquivRel(T;x,y.x R y)
  ⇒ (∀Q:(x,y:T//(x R y)) ⟶ (x,y:T//(x R y)) ⟶ ℙ
        (EquivRel(x,y:T//(x R y);u,v.u Q v) ⇒ u,v:x,y:T//(x R y)//(u Q v) ≡ x,y:T//(x Q 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,  prop: ℙ,  infix_ap: x f y,  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  so_lambda: λ2x y.t[x; y],  prop: ℙ,  subtype_rel: A ⊆r B,  so_apply: x[s1;s2],  uimplies: b supposing a,  so_lambda: λ2x.t[x],  so_apply: x[s],  istype: istype(T),  ext-eq: A ≡ B,  and: P ∧ Q,  quotient: x,y:A//B[x; y],  infix_ap: x f y,  guard: {T}
Lemmas referenced :  equiv-on-quotient,  quotient_wf,  infix_ap_wf,  subtype_rel_dep_function,  subtype_quotient,  equal-wf-base,  quotient_subtype_quotient,  subtype_rel_self,  equiv_rel_wf,  quotient-member-eq
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  isectElimination,  because_Cache,  sqequalRule,  Error :lambdaEquality_alt,  instantiate,  cumulativity,  universeEquality,  applyEquality,  Error :inhabitedIsType,  independent_isectElimination,  functionEquality,  functionExtensionality,  Error :universeIsType,  independent_pairFormation,  pointwiseFunctionalityForEquality,  pertypeElimination,  productElimination,  equalityTransitivity,  equalitySymmetry,  Error :equalityIsType1,  productEquality,  Error :functionIsType,  hyp_replacement

Latex:
\mforall{}T:Type.  \mforall{}R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}.
    (EquivRel(T;x,y.x  R  y)
    {}\mRightarrow{}  (\mforall{}Q:(x,y:T//(x  R  y))  {}\mrightarrow{}  (x,y:T//(x  R  y))  {}\mrightarrow{}  \mBbbP{}
                (EquivRel(x,y:T//(x  R  y);u,v.u  Q  v)  {}\mRightarrow{}  u,v:x,y:T//(x  R  y)//(u  Q  v)  \mequiv{}  x,y:T//(x  Q  y))))



Date html generated: 2019_06_20-PM-00_33_09
Last ObjectModification: 2018_09_30-PM-00_36_21

Theory : quot_1


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