Nuprl Lemma : isect2_subtype_rel3

∀[A,B,C:Type].  A ⋂ B ⊆r C supposing (A ⊆r C) ∨ (B ⊆r C)


Proof




Definitions occuring in Statement :  isect2: T1 ⋂ T2,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  or: P ∨ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  or: P ∨ Q,  subtype_rel: A ⊆r B,  prop: ℙ
Lemmas referenced :  or_wf,  subtype_rel_wf,  subtype_rel_transitivity,  isect2_wf,  isect2_subtype_rel,  isect2_subtype_rel2
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  unionElimination,  thin,  sqequalRule,  axiomEquality,  hypothesis,  lemma_by_obid,  isectElimination,  hypothesisEquality,  isect_memberEquality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  universeEquality,  independent_isectElimination

Latex:
\mforall{}[A,B,C:Type].    A  \mcap{}  B  \msubseteq{}r  C  supposing  (A  \msubseteq{}r  C)  \mvee{}  (B  \msubseteq{}r  C)



Date html generated: 2016_05_13-PM-03_58_10
Last ObjectModification: 2015_12_26-AM-10_51_07

Theory : bool_1


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