Nuprl Lemma : psc-restriction-comp2

C:SmallCategory. ∀X:ps_context{j:l}(C). ∀I,J1,J2,K:cat-ob(C). ∀f:cat-arrow(C) J1 I. ∀g:cat-arrow(C) J1. ∀a:X(I).
  g(f(a)) cat-comp(C) J1 f(a) ∈ X(K) supposing J1 J2 ∈ cat-ob(C)


Proof




Definitions occuring in Statement :  psc-restriction: f(s) I_set: A(I) ps_context: __⊢ uimplies: supposing a all: x:A. B[x] apply: a equal: t ∈ T cat-comp: cat-comp(C) cat-arrow: cat-arrow(C) cat-ob: cat-ob(C) small-category: SmallCategory
Definitions unfolded in proof :  all: x:A. B[x] uimplies: supposing a member: t ∈ T squash: T uall: [x:A]. B[x] subtype_rel: A ⊆B and: P ∧ Q true: True guard: {T} iff: ⇐⇒ Q rev_implies:  Q implies:  Q
Lemmas referenced :  equal_wf I_set_wf psc-restriction_wf small-category-cumulativity-2 ps_context_cumulativity2 subtype_rel-equal cat-arrow_wf cat-comp_wf iff_weakening_equal psc-restriction-comp
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt isect_memberFormation_alt cut applyEquality thin instantiate lambdaEquality_alt sqequalHypSubstitution imageElimination introduction extract_by_obid isectElimination because_Cache hypothesis hypothesisEquality sqequalRule independent_isectElimination equalitySymmetry dependent_set_memberEquality_alt independent_pairFormation equalityTransitivity productIsType equalityIstype inhabitedIsType applyLambdaEquality setElimination rename productElimination natural_numberEquality imageMemberEquality baseClosed independent_functionElimination dependent_functionElimination universeIsType

Latex:
\mforall{}C:SmallCategory.  \mforall{}X:ps\_context\{j:l\}(C).  \mforall{}I,J1,J2,K:cat-ob(C).  \mforall{}f:cat-arrow(C)  J1  I.
\mforall{}g:cat-arrow(C)  K  J1.  \mforall{}a:X(I).
    g(f(a))  =  cat-comp(C)  K  J1  I  g  f(a)  supposing  J1  =  J2



Date html generated: 2020_05_20-PM-01_24_33
Last ObjectModification: 2020_04_01-AM-11_00_38

Theory : presheaf!models!of!type!theory


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