Nuprl Lemma : subtype_rel_b-union

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


Proof




Definitions occuring in Statement :  b-union: A ⋃ B uimplies: supposing a subtype_rel: A ⊆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: supposing a and: P ∧ Q so_lambda: λ2x.t[x] so_apply: x[s] subtype_rel: A ⊆B all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] prop: 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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