Nuprl Lemma : union_functionality_wrt_iff
∀[P1,P2,Q1,Q2:ℙ].  ({P1 
⇐⇒ P2} 
⇒ {Q1 
⇐⇒ Q2} 
⇒ {P1 + Q1 
⇐⇒ P2 + Q2})
Proof
Definitions occuring in Statement : 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
union: left + right
Definitions unfolded in proof : 
guard: {T}
, 
or: P ∨ Q
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
or_wf, 
iff_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
Error :isect_memberFormation_alt, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
independent_pairFormation, 
unionElimination, 
inlFormation, 
independent_functionElimination, 
hypothesis, 
hypothesisEquality, 
inrFormation, 
cut, 
introduction, 
extract_by_obid, 
isectElimination, 
Error :inhabitedIsType, 
Error :universeIsType, 
universeEquality
Latex:
\mforall{}[P1,P2,Q1,Q2:\mBbbP{}].    (\{P1  \mLeftarrow{}{}\mRightarrow{}  P2\}  {}\mRightarrow{}  \{Q1  \mLeftarrow{}{}\mRightarrow{}  Q2\}  {}\mRightarrow{}  \{P1  +  Q1  \mLeftarrow{}{}\mRightarrow{}  P2  +  Q2\})
Date html generated:
2019_06_20-AM-11_17_19
Last ObjectModification:
2018_09_26-AM-10_24_46
Theory : core_2
Home
Index