Nuprl Lemma : qmax-assoc
∀[x,y,z:ℚ].  (qmax(qmax(x;y);z) = qmax(x;qmax(y;z)) ∈ ℚ)
Proof
Definitions occuring in Statement : 
qmax: qmax(x;y), 
rationals: ℚ, 
uall: ∀[x:A]. B[x], 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
qmax: qmax(x;y), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
prop: ℙ, 
guard: {T}, 
iff: P ⇐⇒ Q, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
false: False, 
squash: ↓T, 
true: True, 
subtype_rel: A ⊆r B, 
not: ¬A
Lemmas referenced : 
q_le_wf, 
bool_wf, 
eqtt_to_assert, 
assert-q_le-eq, 
iff_weakening_equal, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
not_wf, 
qle_transitivity_qorder, 
squash_wf, 
true_wf, 
qle_complement_qorder, 
qless_transitivity_2_qorder, 
qless_transitivity, 
qless_irreflexivity
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
independent_isectElimination, 
independent_functionElimination, 
sqequalRule, 
because_Cache, 
dependent_pairFormation, 
promote_hyp, 
dependent_functionElimination, 
instantiate, 
cumulativity, 
voidElimination, 
applyEquality, 
lambdaEquality, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[x,y,z:\mBbbQ{}].    (qmax(qmax(x;y);z)  =  qmax(x;qmax(y;z)))
Date html generated:
2018_05_21-PM-11_55_27
Last ObjectModification:
2017_07_26-PM-06_46_13
Theory : rationals
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