Nuprl Lemma : hdf-until-ap-fst

[A,B,C:Type]. ∀[X:hdataflow(A;B)]. ∀[Y:hdataflow(A;C)]. ∀[a:A].
  ((fst(hdf-until(X;Y)(a)))
  if bag-null(snd(Y(a))) then hdf-until(fst(X(a));fst(Y(a))) else hdf-halt() fi 
  ∈ hdataflow(A;B))


Proof




Definitions occuring in Statement :  hdf-until: hdf-until(X;Y) hdf-halt: hdf-halt() hdf-ap: X(a) hdataflow: hdataflow(A;B) ifthenelse: if then else fi  uall: [x:A]. B[x] pi1: fst(t) pi2: snd(t) universe: Type equal: t ∈ T bag-null: bag-null(bs)
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T true: True all: x:A. B[x] implies:  Q so_lambda: λ2x.t[x] so_apply: x[s] bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a subtype_rel: A ⊆B top: Top bfalse: ff exists: x:A. B[x] prop: or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False not: ¬A pi1: fst(t) squash: T iff: ⇐⇒ Q rev_implies:  Q

Latex:
\mforall{}[A,B,C:Type].  \mforall{}[X:hdataflow(A;B)].  \mforall{}[Y:hdataflow(A;C)].  \mforall{}[a:A].
    ((fst(hdf-until(X;Y)(a)))
    =  if  bag-null(snd(Y(a)))  then  hdf-until(fst(X(a));fst(Y(a)))  else  hdf-halt()  fi  )



Date html generated: 2016_05_16-AM-10_41_09
Last ObjectModification: 2016_01_17-AM-11_11_48

Theory : halting!dataflow


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