Nuprl Lemma : co-retraction-monic

[C:SmallCategory]. ∀[y,z:cat-ob(C)]. ∀[f:cat-arrow(C) z].  monic(f) supposing co-retraction(f)


Proof




Definitions occuring in Statement :  cat-monic: monic(f) cat-co-retraction: co-retraction(f) cat-arrow: cat-arrow(C) cat-ob: cat-ob(C) small-category: SmallCategory uimplies: supposing a uall: [x:A]. B[x] apply: a
Definitions unfolded in proof :  uall: [x:A]. B[x] uimplies: supposing a cat-monic: monic(f) member: t ∈ T cat-co-retraction: co-retraction(f) exists: x:A. B[x] cat-inverse: fg=1 prop: true: True squash: T all: x:A. B[x] subtype_rel: A ⊆B and: P ∧ Q guard: {T} iff: ⇐⇒ Q implies:  Q
Lemmas referenced :  equal_wf cat-arrow_wf cat-comp_wf cat-co-retraction_wf cat-ob_wf small-category_wf squash_wf true_wf cat-comp-assoc cat-comp-ident iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalHypSubstitution productElimination thin rename hypothesis extract_by_obid isectElimination applyEquality hypothesisEquality sqequalRule isect_memberEquality axiomEquality because_Cache equalityTransitivity equalitySymmetry applyLambdaEquality natural_numberEquality lambdaEquality imageElimination universeEquality dependent_functionElimination imageMemberEquality baseClosed independent_isectElimination independent_functionElimination

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[y,z:cat-ob(C)].  \mforall{}[f:cat-arrow(C)  y  z].    monic(f)  supposing  co-retraction(f)



Date html generated: 2017_10_05-AM-00_45_50
Last ObjectModification: 2017_07_28-AM-09_19_07

Theory : small!categories


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