Nuprl Lemma : and-iff
∀[A:ℙ]. ∀[B,C:⋂a:A. ℙ].  ((A 
⇒ (B 
⇐⇒ C)) 
⇒ {A ∧ B 
⇐⇒ A ∧ C})
Proof
Definitions occuring in Statement : 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
isect: ⋂x:A. B[x]
Definitions unfolded in proof : 
guard: {T}
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
iff_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
hypothesis, 
independent_functionElimination, 
productEquality, 
cumulativity, 
hypothesisEquality, 
cut, 
rename, 
isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
functionEquality, 
lemma_by_obid, 
applyEquality, 
lambdaEquality, 
isectEquality, 
universeEquality
Latex:
\mforall{}[A:\mBbbP{}].  \mforall{}[B,C:\mcap{}a:A.  \mBbbP{}].    ((A  {}\mRightarrow{}  (B  \mLeftarrow{}{}\mRightarrow{}  C))  {}\mRightarrow{}  \{A  \mwedge{}  B  \mLeftarrow{}{}\mRightarrow{}  A  \mwedge{}  C\})
Date html generated:
2016_05_13-PM-03_13_08
Last ObjectModification:
2016_01_06-PM-05_23_28
Theory : core_2
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