Nuprl Lemma : cat-comp-assoc

[C:SmallCategory]
  ∀x,y,z,w:cat-ob(C). ∀f:cat-arrow(C) y. ∀g:cat-arrow(C) z. ∀h:cat-arrow(C) w.
    ((cat-comp(C) (cat-comp(C) g) h) (cat-comp(C) (cat-comp(C) h)) ∈ (cat-arrow(C) w))


Proof




Definitions occuring in Statement :  cat-comp: cat-comp(C) cat-arrow: cat-arrow(C) cat-ob: cat-ob(C) small-category: SmallCategory uall: [x:A]. B[x] all: x:A. B[x] apply: a equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] small-category: SmallCategory cat-arrow: cat-arrow(C) pi2: snd(t) pi1: fst(t) cat-ob: cat-ob(C) cat-comp: cat-comp(C) spreadn: spread4 and: P ∧ Q squash: T prop: true: True subtype_rel: A ⊆B uimplies: supposing a guard: {T} iff: ⇐⇒ Q rev_implies:  Q implies:  Q
Lemmas referenced :  equal_wf squash_wf true_wf iff_weakening_equal cat-arrow_wf cat-ob_wf small-category_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lambdaFormation sqequalHypSubstitution setElimination thin rename productElimination sqequalRule applyEquality lambdaEquality imageElimination extract_by_obid isectElimination hypothesisEquality equalityTransitivity hypothesis equalitySymmetry universeEquality functionExtensionality cumulativity dependent_functionElimination because_Cache natural_numberEquality imageMemberEquality baseClosed independent_isectElimination independent_functionElimination axiomEquality

Latex:
\mforall{}[C:SmallCategory]
    \mforall{}x,y,z,w:cat-ob(C).  \mforall{}f:cat-arrow(C)  x  y.  \mforall{}g:cat-arrow(C)  y  z.  \mforall{}h:cat-arrow(C)  z  w.
        ((cat-comp(C)  x  z  w  (cat-comp(C)  x  y  z  f  g)  h)  =  (cat-comp(C)  x  y  w  f  (cat-comp(C)  y  z  w  g  h)))



Date html generated: 2020_05_20-AM-07_49_57
Last ObjectModification: 2017_07_28-AM-09_18_59

Theory : small!categories


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