Nuprl Lemma : add-monotonic
∀a,b,c,d:ℤ.  (a < b ⇒ ((c = d ∈ ℤ) ∨ c < d) ⇒ a + c < b + d)
Proof
Definitions occuring in Statement : 
less_than: a < b, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
or: P ∨ Q, 
add: n + m, 
int: ℤ, 
equal: s = t ∈ T
Definitions unfolded in proof : 
subtype_rel: A ⊆r B, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
squash: ↓T, 
member: t ∈ T, 
less_than': less_than'(a;b), 
cand: A c∧ B, 
and: P ∧ Q, 
less_than: a < b, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
not: ¬A, 
false: False, 
or: P ∨ Q, 
decidable: Dec(P), 
sq_type: SQType(T), 
rev_implies: P ⇐ Q, 
iff: P ⇐⇒ Q, 
guard: {T}, 
uimplies: b supposing a, 
top: Top, 
true: True
Lemmas referenced : 
less_than_wf, 
int_subtype_base, 
equal-wf-base, 
or_wf, 
decidable__less_than', 
subtype_base_sq, 
iff_weakening_equal, 
false_wf, 
true_wf, 
top_wf, 
add-comm
Rules used in proof : 
applyEquality, 
intEquality, 
isectElimination, 
extract_by_obid, 
sqequalHypSubstitution, 
baseClosed, 
thin, 
imageMemberEquality, 
sqequalRule, 
introduction, 
hypothesisEquality, 
addEquality, 
hypothesis, 
independent_pairFormation, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
addMonotonic, 
voidElimination, 
independent_functionElimination, 
productElimination, 
imageElimination, 
unionElimination, 
dependent_functionElimination, 
cumulativity, 
instantiate, 
independent_isectElimination, 
voidEquality, 
promote_hyp, 
because_Cache, 
isect_memberEquality, 
axiomSqEquality, 
isect_memberFormation, 
natural_numberEquality, 
equalityTransitivity, 
lessCases, 
sqequalBase, 
equalitySymmetry, 
baseInt, 
Error :lessTransitive
Latex:
\mforall{}a,b,c,d:\mBbbZ{}.    (a  <  b  {}\mRightarrow{}  ((c  =  d)  \mvee{}  c  <  d)  {}\mRightarrow{}  a  +  c  <  b  +  d)
Date html generated:
2019_06_20-AM-11_19_49
Last ObjectModification:
2018_10_15-AM-08_55_51
Theory : sqequal_1
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