Nuprl Lemma : biject-quotient

A,B:Type. ∀f:A ⟶ B. ∀R:B ⟶ B ⟶ ℙ.
  (Bij(A;B;f)  EquivRel(B;x,y.x y)  Bij(x,y:A//(x R_f y);x,y:B//(x y);quo-lift(f)))


Proof




Definitions occuring in Statement :  quo-lift: quo-lift(f) preima_of_rel: R_f equiv_rel: EquivRel(T;x,y.E[x; y]) biject: Bij(A;B;f) quotient: x,y:A//B[x; y] prop: infix_ap: y all: x:A. B[x] implies:  Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T biject: Bij(A;B;f) and: P ∧ Q cand: c∧ B inject: Inj(A;B;f) uall: [x:A]. B[x] so_lambda: λ2y.t[x; y] infix_ap: y so_apply: x[s1;s2] uimplies: supposing a surject: Surj(A;B;f) prop: quotient: x,y:A//B[x; y] preima_of_rel: R_f subtype_rel: A ⊆B quo-lift: quo-lift(f) equiv_rel: EquivRel(T;x,y.E[x; y]) trans: Trans(T;x,y.E[x; y]) exists: x:A. B[x] pi1: fst(t) rev_implies:  Q iff: ⇐⇒ Q guard: {T}
Lemmas referenced :  preima_of_equiv_rel quo-lift_wf quotient_wf preima_of_rel_wf equiv_rel_wf biject_wf istype-universe infix_ap_wf subtype_rel_self quotient-member-eq iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :lambdaFormation_alt,  cut introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality independent_functionElimination hypothesis because_Cache productElimination Error :equalityIstype,  Error :universeIsType,  isectElimination sqequalRule Error :lambdaEquality_alt,  applyEquality Error :inhabitedIsType,  independent_isectElimination independent_pairFormation Error :functionIsType,  universeEquality instantiate pointwiseFunctionalityForEquality cumulativity pertypeElimination Error :productIsType,  sqequalBase equalitySymmetry equalityTransitivity Error :equalityIsType1,  promote_hyp rename Error :dependent_pairFormation_alt,  functionExtensionality Error :equalityIsType4

Latex:
\mforall{}A,B:Type.  \mforall{}f:A  {}\mrightarrow{}  B.  \mforall{}R:B  {}\mrightarrow{}  B  {}\mrightarrow{}  \mBbbP{}.
    (Bij(A;B;f)  {}\mRightarrow{}  EquivRel(B;x,y.x  R  y)  {}\mRightarrow{}  Bij(x,y:A//(x  R\_f  y);x,y:B//(x  R  y);quo-lift(f)))



Date html generated: 2019_06_20-PM-00_33_19
Last ObjectModification: 2018_11_24-AM-09_34_34

Theory : quot_1


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