Nuprl Lemma : radd-rneq0
∀x,y:ℝ.  (x + y ≠ r0 ⇐⇒ x ≠ -(y))
Proof
Definitions occuring in Statement : 
rneq: x ≠ y, 
rminus: -(x), 
radd: a + b, 
int-to-real: r(n), 
real: ℝ, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
rev_implies: P ⇐ Q, 
rneq: x ≠ y, 
or: P ∨ Q, 
uimplies: b supposing a, 
uiff: uiff(P;Q), 
req_int_terms: t1 ≡ t2, 
false: False, 
not: ¬A, 
top: Top
Lemmas referenced : 
rneq_wf, 
radd_wf, 
int-to-real_wf, 
rminus_wf, 
real_wf, 
radd-preserves-rless, 
rless_wf, 
itermSubtract_wf, 
itermAdd_wf, 
itermVar_wf, 
itermMinus_wf, 
itermConstant_wf, 
rless_functionality, 
req-iff-rsub-is-0, 
real_polynomial_null, 
istype-int, 
real_term_value_sub_lemma, 
istype-void, 
real_term_value_add_lemma, 
real_term_value_var_lemma, 
real_term_value_const_lemma, 
real_term_value_minus_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
independent_pairFormation, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
inhabitedIsType, 
unionElimination, 
inlFormation_alt, 
dependent_functionElimination, 
productElimination, 
independent_functionElimination, 
inrFormation_alt, 
because_Cache, 
independent_isectElimination, 
sqequalRule, 
approximateComputation, 
lambdaEquality_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination
Latex:
\mforall{}x,y:\mBbbR{}.    (x  +  y  \mneq{}  r0  \mLeftarrow{}{}\mRightarrow{}  x  \mneq{}  -(y))
 Date html generated: 
2019_10_29-AM-09_57_53
 Last ObjectModification: 
2019_04_01-PM-05_33_11
Theory : reals
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