Nuprl Lemma : psc_map_cumulativity2

[C:SmallCategory]. ∀[X,Y,Z,U:ps_context{j:l}(C)].
  (psc_map{j:l}(C; X; Z) ⊆psc_map{j:l}(C; Y; U)) supposing 
     (sub_ps_context{j:l}(C; Y; X) and 
     sub_ps_context{j:l}(C; Z; U))


Proof




Definitions occuring in Statement :  sub_ps_context: Y ⊆ X psc_map: A ⟶ B ps_context: __⊢ uimplies: supposing a subtype_rel: A ⊆B uall: [x:A]. B[x] small-category: SmallCategory
Definitions unfolded in proof :  uall: [x:A]. B[x] uimplies: supposing a member: t ∈ T subtype_rel: A ⊆B istype: istype(T)
Lemmas referenced :  sub_ps_context_wf ps_context_wf small-category-cumulativity-2 small-category_wf psc_map_wf psc_map_subtype3 subtype_rel_transitivity
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt universeIsType cut thin instantiate introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality applyEquality because_Cache hypothesis sqequalRule independent_isectElimination lambdaEquality_alt

Latex:
\mforall{}[C:SmallCategory].  \mforall{}[X,Y,Z,U:ps\_context\{j:l\}(C)].
    (psc\_map\{j:l\}(C;  X;  Z)  \msubseteq{}r  psc\_map\{j:l\}(C;  Y;  U))  supposing 
          (sub\_ps\_context\{j:l\}(C;  Y;  X)  and 
          sub\_ps\_context\{j:l\}(C;  Z;  U))



Date html generated: 2020_05_20-PM-01_25_12
Last ObjectModification: 2020_04_01-PM-00_17_51

Theory : presheaf!models!of!type!theory


Home Index