Nuprl Lemma : cat-comp-ident
∀[C:SmallCategory]
  ∀x,y:cat-ob(C). ∀f:cat-arrow(C) x y.
    (((cat-comp(C) x x y (cat-id(C) x) f) = f ∈ (cat-arrow(C) x y))
    ∧ ((cat-comp(C) x y y f (cat-id(C) y)) = f ∈ (cat-arrow(C) x y)))
Proof
Definitions occuring in Statement : 
cat-comp: cat-comp(C)
, 
cat-id: cat-id(C)
, 
cat-arrow: cat-arrow(C)
, 
cat-ob: cat-ob(C)
, 
small-category: SmallCategory
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
apply: f a
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
guard: {T}
, 
cand: A c∧ B
, 
and: P ∧ Q
, 
spreadn: spread4, 
cat-comp: cat-comp(C)
, 
cat-id: cat-id(C)
, 
cat-ob: cat-ob(C)
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
cat-arrow: cat-arrow(C)
, 
small-category: SmallCategory
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
small-category_wf, 
cat-ob_wf, 
cat-arrow_wf
Rules used in proof : 
because_Cache, 
axiomEquality, 
independent_pairEquality, 
dependent_functionElimination, 
lambdaEquality, 
hypothesisEquality, 
isectElimination, 
lemma_by_obid, 
applyEquality, 
hypothesis, 
independent_pairFormation, 
sqequalRule, 
productElimination, 
rename, 
thin, 
setElimination, 
sqequalHypSubstitution, 
lambdaFormation, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[C:SmallCategory]
    \mforall{}x,y:cat-ob(C).  \mforall{}f:cat-arrow(C)  x  y.
        (((cat-comp(C)  x  x  y  (cat-id(C)  x)  f)  =  f)  \mwedge{}  ((cat-comp(C)  x  y  y  f  (cat-id(C)  y))  =  f))
Date html generated:
2016_05_18-AM-11_52_12
Last ObjectModification:
2015_12_28-PM-02_23_55
Theory : small!categories
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