Nuprl Lemma : member-ite

b:𝔹. ∀[T:Type]. ∀A,B:T List. ∀x:T.  ((x ∈ if then else fi ⇐⇒ ((↑b) ∧ (x ∈ A)) ∨ ((¬↑b) ∧ (x ∈ B)))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l) list: List assert: b ifthenelse: if then else fi  bool: 𝔹 uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q not: ¬A or: P ∨ Q and: P ∧ Q universe: Type
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uall: [x:A]. B[x] uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a ifthenelse: if then else fi  assert: b iff: ⇐⇒ Q or: P ∨ Q cand: c∧ B prop: rev_implies:  Q not: ¬A true: True false: False bfalse: ff exists: x:A. B[x] sq_type: SQType(T) guard: {T} bnot: ¬bb

Latex:
\mforall{}b:\mBbbB{}
    \mforall{}[T:Type]
        \mforall{}A,B:T  List.  \mforall{}x:T.    ((x  \mmember{}  if  b  then  A  else  B  fi  )  \mLeftarrow{}{}\mRightarrow{}  ((\muparrow{}b)  \mwedge{}  (x  \mmember{}  A))  \mvee{}  ((\mneg{}\muparrow{}b)  \mwedge{}  (x  \mmember{}  B)))



Date html generated: 2016_05_16-AM-10_23_11
Last ObjectModification: 2015_12_28-PM-09_20_26

Theory : new!event-ordering


Home Index