Nuprl Lemma : co-retraction-monic
∀[C:SmallCategory]. ∀[y,z:cat-ob(C)]. ∀[f:cat-arrow(C) y 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: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
apply: f a
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b 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: ℙ
, 
true: True
, 
squash: ↓T
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
and: P ∧ Q
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ 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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