Nuprl Lemma : tunion-value-type

[A:Type]. ∀[B:A ⟶ Type].  value-type(⋃a:A.B[a]) supposing ∀a:A. value-type(B[a])


Proof




Definitions occuring in Statement :  value-type: value-type(T) uimplies: supposing a tunion: x:A.B[x] uall: [x:A]. B[x] so_apply: x[s] all: x:A. B[x] function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a value-type: value-type(T) sq_stable: SqStable(P) implies:  Q so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] tunion: x:A.B[x] has-value: (a)↓ top: Top pi1: fst(t) prop: squash: T guard: {T}
Lemmas referenced :  sq_stable__has-value tunion_wf value-type-has-value pi1_wf pi2_wf top_wf equal_wf equal-wf-base base_wf all_wf value-type_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis independent_functionElimination equalityTransitivity equalitySymmetry cumulativity sqequalRule lambdaEquality applyEquality functionExtensionality lambdaFormation imageElimination productElimination dependent_pairEquality independent_isectElimination independent_pairEquality isect_memberEquality voidElimination voidEquality productEquality dependent_functionElimination imageMemberEquality baseClosed because_Cache axiomSqleEquality functionEquality universeEquality

Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].    value-type(\mcup{}a:A.B[a])  supposing  \mforall{}a:A.  value-type(B[a])



Date html generated: 2017_04_14-AM-07_15_02
Last ObjectModification: 2017_02_27-PM-02_50_33

Theory : call!by!value_1


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