Nuprl Lemma : quo-lift_wf

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


Proof




Definitions occuring in Statement :  quo-lift: quo-lift(f) preima_of_rel: R_f equiv_rel: EquivRel(T;x,y.E[x; y]) quotient: x,y:A//B[x; y] prop: infix_ap: y all: x:A. B[x] implies:  Q member: t ∈ T function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T uall: [x:A]. B[x] so_lambda: λ2y.t[x; y] infix_ap: y so_apply: x[s1;s2] uimplies: supposing a quotient: x,y:A//B[x; y] and: P ∧ Q prop: subtype_rel: A ⊆B preima_of_rel: R_f quo-lift: quo-lift(f)
Lemmas referenced :  preima_of_equiv_rel quotient_wf equal-wf-base preima_of_rel_wf equiv_rel_wf quotient-member-eq
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality independent_functionElimination hypothesis functionExtensionality pointwiseFunctionalityForEquality isectElimination cumulativity sqequalRule lambdaEquality applyEquality independent_isectElimination pertypeElimination productElimination productEquality because_Cache universeEquality functionEquality

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



Date html generated: 2016_10_21-AM-09_44_13
Last ObjectModification: 2016_08_08-PM-09_15_45

Theory : quot_1


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