Nuprl Lemma : strong-subtype-discrete-type
∀[A,B:Type].  (discrete-type(A)) supposing (discrete-type(B) and strong-subtype(A;B))
Proof
Definitions occuring in Statement : 
discrete-type: discrete-type(T)
, 
strong-subtype: strong-subtype(A;B)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
discrete-type: discrete-type(T)
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
strong-subtype: strong-subtype(A;B)
, 
cand: A c∧ B
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
guard: {T}
Lemmas referenced : 
req_wf, 
real_wf, 
all_wf, 
equal_wf, 
discrete-type_wf, 
strong-subtype_wf, 
exists_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
lambdaFormation, 
hypothesis, 
dependent_functionElimination, 
thin, 
functionExtensionality, 
applyEquality, 
hypothesisEquality, 
productElimination, 
sqequalRule, 
because_Cache, 
independent_functionElimination, 
extract_by_obid, 
isectElimination, 
lambdaEquality, 
functionEquality, 
cumulativity, 
axiomEquality, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
dependent_set_memberEquality, 
dependent_pairFormation
Latex:
\mforall{}[A,B:Type].    (discrete-type(A))  supposing  (discrete-type(B)  and  strong-subtype(A;B))
Date html generated:
2018_05_22-PM-02_13_27
Last ObjectModification:
2017_10_30-AM-00_37_14
Theory : reals
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