Nuprl Lemma : subtype_rel_double_isect

[A,T1,T2:Type]. ∀[B:T1 ⟶ T2 ⟶ Type].  uiff(A ⊆(⋂x:T1. ⋂y:T2.  B[x;y]);∀[x:T1]. ∀[y:T2].  (A ⊆B[x;y]))


Proof




Definitions occuring in Statement :  uiff: uiff(P;Q) subtype_rel: A ⊆B uall: [x:A]. B[x] so_apply: x[s1;s2] isect: x:A. B[x] function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a subtype_rel: A ⊆B so_apply: x[s1;s2] prop: so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] implies:  Q
Lemmas referenced :  subtype_rel_wf uall_wf subtype_rel_transitivity equal_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut independent_pairFormation sqequalRule axiomEquality hypothesis hypothesisEquality sqequalHypSubstitution isect_memberEquality isectElimination thin because_Cache extract_by_obid cumulativity isectEquality applyEquality functionExtensionality lambdaEquality productElimination independent_pairEquality equalityTransitivity equalitySymmetry functionEquality universeEquality independent_isectElimination lambdaFormation dependent_functionElimination independent_functionElimination

Latex:
\mforall{}[A,T1,T2:Type].  \mforall{}[B:T1  {}\mrightarrow{}  T2  {}\mrightarrow{}  Type].
    uiff(A  \msubseteq{}r  (\mcap{}x:T1.  \mcap{}y:T2.    B[x;y]);\mforall{}[x:T1].  \mforall{}[y:T2].    (A  \msubseteq{}r  B[x;y]))



Date html generated: 2017_04_14-AM-07_14_03
Last ObjectModification: 2017_02_27-PM-02_49_46

Theory : subtype_0


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