Nuprl Lemma : rless*_functionality
∀a,b,c,d:ℝ*.  (a = b 
⇒ c = d 
⇒ (a < c 
⇐⇒ b < d))
Proof
Definitions occuring in Statement : 
rless*: x < y
, 
req*: x = y
, 
real*: ℝ*
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rless*: x < y
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
rev_implies: P 
⇐ Q
, 
guard: {T}
, 
uimplies: b supposing a
Lemmas referenced : 
rless*_wf, 
req*_wf, 
real*_wf, 
rrel*_functionality, 
rless_wf, 
real_wf, 
req_inversion, 
rless_transitivity2, 
rleq_weakening, 
rless_transitivity1, 
req_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
independent_pairFormation, 
sqequalHypSubstitution, 
cut, 
introduction, 
extract_by_obid, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
lambdaEquality, 
independent_functionElimination, 
sqequalRule, 
independent_isectElimination, 
dependent_functionElimination, 
because_Cache, 
productElimination
Latex:
\mforall{}a,b,c,d:\mBbbR{}*.    (a  =  b  {}\mRightarrow{}  c  =  d  {}\mRightarrow{}  (a  <  c  \mLeftarrow{}{}\mRightarrow{}  b  <  d))
Date html generated:
2018_05_22-PM-03_20_17
Last ObjectModification:
2017_10_06-PM-06_05_48
Theory : reals_2
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