Nuprl Lemma : qmax-eq-iff-cases
∀q,r,s:ℚ.  uiff(qmax(q;r) = s ∈ ℚ;((r ≤ q) ∧ (s = q ∈ ℚ)) ∨ ((q ≤ r) ∧ (s = r ∈ ℚ)))
Proof
Definitions occuring in Statement : 
qmax: qmax(x;y), 
qle: r ≤ s, 
rationals: ℚ, 
uiff: uiff(P;Q), 
all: ∀x:A. B[x], 
or: P ∨ Q, 
and: P ∧ Q, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
qmax: qmax(x;y), 
member: t ∈ T, 
uall: ∀[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 , 
or: P ∨ Q, 
cand: A c∧ B, 
false: False, 
bfalse: ff, 
exists: ∃x:A. B[x], 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
not: ¬A, 
rev_implies: P ⇐ Q
Lemmas referenced : 
q_le_wf, 
eqtt_to_assert, 
assert-q_le-eq, 
iff_weakening_equal, 
qless_trichot_qorder, 
qless_transitivity_2_qorder, 
qless_irreflexivity, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
qle_wf, 
qle_weakening_lt_qorder, 
qle_weakening_eq_qorder, 
rationals_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
inhabitedIsType, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
independent_isectElimination, 
independent_functionElimination, 
sqequalRule, 
dependent_functionElimination, 
independent_pairFormation, 
isect_memberFormation_alt, 
axiomEquality, 
rename, 
inrFormation_alt, 
because_Cache, 
voidElimination, 
dependent_pairFormation_alt, 
equalityIstype, 
promote_hyp, 
instantiate, 
cumulativity, 
universeIsType, 
inlFormation_alt
Latex:
\mforall{}q,r,s:\mBbbQ{}.    uiff(qmax(q;r)  =  s;((r  \mleq{}  q)  \mwedge{}  (s  =  q))  \mvee{}  ((q  \mleq{}  r)  \mwedge{}  (s  =  r)))
Date html generated:
2020_05_20-AM-09_16_42
Last ObjectModification:
2019_11_02-PM-00_42_22
Theory : rationals
Home
Index