Nuprl Lemma : dep-isect-subtype2
∀[A1,A2:Type]. ∀[B1:A1 ⟶ Type]. ∀[B2:A2 ⟶ Type].
  (x:A1 ⋂ B1[x] ⊆r x:A2 ⋂ B2[x]) supposing ((∀x:A1. (B1[x] ⊆r B2[x])) and (A1 ⊆r A2))
Proof
Definitions occuring in Statement : 
dep-isect: x:A ⋂ B[x]
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
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: b supposing a
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
all: ∀x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
prop: ℙ
Lemmas referenced : 
dep-isect-subtype, 
subtype_rel_transitivity, 
dep-isect_wf, 
all_wf, 
subtype_rel_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaEquality, 
dependentIntersectionElimination, 
sqequalHypSubstitution, 
dependentIntersection_memberEquality, 
hypothesisEquality, 
applyEquality, 
thin, 
extract_by_obid, 
dependent_functionElimination, 
sqequalRule, 
hypothesis, 
instantiate, 
isectElimination, 
cumulativity, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
axiomEquality, 
isect_memberEquality, 
because_Cache, 
functionEquality, 
universeEquality
Latex:
\mforall{}[A1,A2:Type].  \mforall{}[B1:A1  {}\mrightarrow{}  Type].  \mforall{}[B2:A2  {}\mrightarrow{}  Type].
    (x:A1  \mcap{}  B1[x]  \msubseteq{}r  x:A2  \mcap{}  B2[x])  supposing  ((\mforall{}x:A1.  (B1[x]  \msubseteq{}r  B2[x]))  and  (A1  \msubseteq{}r  A2))
Date html generated:
2018_05_21-PM-06_21_22
Last ObjectModification:
2018_05_19-PM-05_32_13
Theory : dependent!intersection
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