Nuprl Lemma : req*_functionality
∀[x1,x2,y1,y2:ℝ*].  (x1 = x2 
⇒ y1 = y2 
⇒ (x1 = y1 
⇐⇒ x2 = y2))
Proof
Definitions occuring in Statement : 
req*: x = y
, 
real*: ℝ*
, 
uall: ∀[x:A]. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
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 : 
req*_wf, 
real*_wf, 
req*_transitivity, 
req*_inversion
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
because_Cache
Latex:
\mforall{}[x1,x2,y1,y2:\mBbbR{}*].    (x1  =  x2  {}\mRightarrow{}  y1  =  y2  {}\mRightarrow{}  (x1  =  y1  \mLeftarrow{}{}\mRightarrow{}  x2  =  y2))
Date html generated:
2018_05_22-PM-03_14_38
Last ObjectModification:
2017_10_06-PM-02_09_21
Theory : reals_2
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