Nuprl Lemma : subtype-corec2
∀[A,B:Type ⟶ Type].
  (let P = corec(T.A[T] ⟶ B[T]) in P ⊆r (A[P] ⟶ B[P])) supposing (Continuous+(T.B[T]) and Continuous+(T.A[T]))
Proof
Definitions occuring in Statement : 
corec: corec(T.F[T])
, 
strong-type-continuous: Continuous+(T.F[T])
, 
let: let, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
strong-type-continuous: Continuous+(T.F[T])
, 
ext-eq: A ≡ B
, 
and: P ∧ Q
, 
subtype_rel: A ⊆r B
, 
let: let, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
type-continuous: Continuous(T.F[T])
, 
guard: {T}
, 
prop: ℙ
Lemmas referenced : 
nat_wf, 
corec_subtype, 
continuous-function, 
subtype_rel_weakening, 
corec_wf, 
strong-type-continuous_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
sqequalRule, 
sqequalHypSubstitution, 
isect_memberEquality, 
isectElimination, 
thin, 
hypothesisEquality, 
productElimination, 
independent_pairEquality, 
axiomEquality, 
hypothesis, 
functionEquality, 
cumulativity, 
lemma_by_obid, 
universeEquality, 
rename, 
lambdaEquality, 
applyEquality, 
independent_isectElimination, 
isectEquality
Latex:
\mforall{}[A,B:Type  {}\mrightarrow{}  Type].
    (let  P  =  corec(T.A[T]  {}\mrightarrow{}  B[T])  in
              P  \msubseteq{}r  (A[P]  {}\mrightarrow{}  B[P]))  supposing 
          (Continuous+(T.B[T])  and 
          Continuous+(T.A[T]))
Date html generated:
2016_05_14-AM-06_21_50
Last ObjectModification:
2015_12_26-PM-00_00_09
Theory : co-recursion
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