Nuprl Lemma : rneq-radd
∀x,y,a,b:ℝ.  (x + y ≠ a + b 
⇒ (x ≠ a ∨ y ≠ b))
Proof
Definitions occuring in Statement : 
rneq: x ≠ y
, 
radd: a + b
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
so_lambda: λ2x.t[x]
, 
or: P ∨ Q
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
rge: x ≥ y
, 
guard: {T}
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
Lemmas referenced : 
rless_wf, 
int-to-real_wf, 
rabs_wf, 
rsub_wf, 
radd_wf, 
real_wf, 
rneq-iff-rabs, 
rneq_wf, 
all_wf, 
or_wf, 
radd-positive-implies, 
rless_functionality_wrt_implies, 
rleq_weakening_equal, 
r-triangle-inequality, 
rminus_wf, 
itermSubtract_wf, 
itermAdd_wf, 
itermVar_wf, 
itermMinus_wf, 
req-iff-rsub-is-0, 
rless_functionality, 
req_weakening, 
rabs_functionality, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_add_lemma, 
real_term_value_var_lemma, 
real_term_value_minus_lemma, 
real_term_value_const_lemma
Rules used in proof : 
cut, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesis, 
hypothesisEquality, 
addLevel, 
allFunctionality, 
impliesFunctionality, 
dependent_functionElimination, 
productElimination, 
independent_functionElimination, 
orFunctionality, 
sqequalRule, 
lambdaEquality, 
because_Cache, 
functionEquality, 
independent_isectElimination, 
approximateComputation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality
Latex:
\mforall{}x,y,a,b:\mBbbR{}.    (x  +  y  \mneq{}  a  +  b  {}\mRightarrow{}  (x  \mneq{}  a  \mvee{}  y  \mneq{}  b))
Date html generated:
2017_10_03-AM-08_46_47
Last ObjectModification:
2017_06_21-PM-03_20_06
Theory : reals
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