Nuprl Lemma : qmin_strict_lb
∀a,b,c:ℚ.  (qmin(b;c) < a ⇐⇒ b < a ∨ c < a)
Proof
Definitions occuring in Statement : 
qmin: qmin(x;y), 
qless: r < s, 
rationals: ℚ, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
or: P ∨ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
qmin: qmin(x;y), 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
or: P ∨ Q, 
prop: ℙ, 
rev_implies: P ⇐ Q, 
guard: {T}, 
uimplies: b supposing a, 
true: True, 
uiff: uiff(P;Q), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
squash: ↓T
Lemmas referenced : 
rationals_wf, 
q_le_wf, 
bool_wf, 
equal-wf-T-base, 
assert_wf, 
qle_wf, 
qless_wf, 
qless_transitivity_1_qorder, 
or_wf, 
bnot_wf, 
not_wf, 
qle_complement_qorder, 
qless_transitivity, 
uiff_transitivity2, 
eqtt_to_assert, 
assert-q_le-eq, 
uiff_transitivity, 
eqff_to_assert, 
assert_of_bnot, 
squash_wf, 
true_wf, 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
baseClosed, 
because_Cache, 
independent_pairFormation, 
inlFormation, 
unionElimination, 
independent_isectElimination, 
natural_numberEquality, 
sqequalRule, 
inrFormation, 
productElimination, 
equalityElimination, 
independent_functionElimination, 
applyEquality, 
lambdaEquality, 
imageElimination, 
universeEquality, 
imageMemberEquality, 
dependent_functionElimination
Latex:
\mforall{}a,b,c:\mBbbQ{}.    (qmin(b;c)  <  a  \mLeftarrow{}{}\mRightarrow{}  b  <  a  \mvee{}  c  <  a)
Date html generated:
2018_05_21-PM-11_55_36
Last ObjectModification:
2017_07_26-PM-06_46_19
Theory : rationals
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