Nuprl Lemma : rless-case_wf
∀[x,y:ℝ]. ∀[n:x < y]. ∀[z:ℝ].  (rless-case(x;y;n;z) ∈ (x < z) ∨ (z < y))
Proof
Definitions occuring in Statement : 
rless-case: rless-case(x;y;n;z), 
rless: x < y, 
real: ℝ, 
uall: ∀[x:A]. B[x], 
or: P ∨ Q, 
member: t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
rless-cases, 
or: P ∨ Q, 
prop: ℙ, 
uimplies: b supposing a, 
rless: x < y, 
sq_exists: ∃x:A [B[x]], 
so_lambda: λ2x.t[x], 
real: ℝ, 
so_apply: x[s], 
nat_plus: ℕ+, 
rless-case: rless-case(x;y;n;z), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
subtype_rel: A ⊆r B, 
sq_type: SQType(T), 
guard: {T}
Lemmas referenced : 
rless-cases, 
subtype_base_sq, 
or_wf, 
rless_wf, 
union_subtype_base, 
set_subtype_base, 
nat_plus_wf, 
less_than_wf, 
int_subtype_base, 
real_wf, 
all_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
cumulativity, 
hypothesisEquality, 
independent_isectElimination, 
sqequalRule, 
lambdaEquality, 
addEquality, 
applyEquality, 
setElimination, 
rename, 
natural_numberEquality, 
intEquality, 
because_Cache, 
functionExtensionality, 
functionEquality, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
axiomEquality, 
isect_memberEquality
Latex:
\mforall{}[x,y:\mBbbR{}].  \mforall{}[n:x  <  y].  \mforall{}[z:\mBbbR{}].    (rless-case(x;y;n;z)  \mmember{}  (x  <  z)  \mvee{}  (z  <  y))
Date html generated:
2018_05_22-PM-01_46_13
Last ObjectModification:
2017_10_26-PM-10_54_06
Theory : reals
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