Nuprl Lemma : subtype_rel_b-union

∀[A1,B1,A2,B2:Type].  (A1 ⋃ B1) ⊆r (A2 ⋃ B2) supposing (A1 ⊆r A2) ∧ (B1 ⊆r B2)


Proof




Definitions occuring in Statement :  b-union: A ⋃ B,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  and: P ∧ Q,  universe: Type
Definitions unfolded in proof :  b-union: A ⋃ B,  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  and: P ∧ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  prop: ℙ,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False
Lemmas referenced :  subtype_rel_tunion,  bool_wf,  ifthenelse_wf,  eqtt_to_assert,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  subtype_rel_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  productElimination,  thin,  extract_by_obid,  isectElimination,  hypothesis,  lambdaEquality,  instantiate,  hypothesisEquality,  universeEquality,  cumulativity,  because_Cache,  independent_isectElimination,  lambdaFormation,  unionElimination,  equalityElimination,  dependent_pairFormation,  promote_hyp,  dependent_functionElimination,  independent_functionElimination,  voidElimination,  equalityTransitivity,  equalitySymmetry,  axiomEquality,  productEquality,  isect_memberEquality

Latex:
\mforall{}[A1,B1,A2,B2:Type].    (A1  \mcup{}  B1)  \msubseteq{}r  (A2  \mcup{}  B2)  supposing  (A1  \msubseteq{}r  A2)  \mwedge{}  (B1  \msubseteq{}r  B2)



Date html generated: 2017_04_14-AM-07_30_21
Last ObjectModification: 2017_02_27-PM-02_59_05

Theory : bool_1


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