Nuprl Lemma : imin-imax-absorption
∀[x,y:ℤ].  (imin(x;imax(x;y)) = x ∈ ℤ)
Proof
Definitions occuring in Statement : 
imin: imin(a;b)
, 
imax: imax(a;b)
, 
uall: ∀[x:A]. B[x]
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
imax: imax(a;b)
, 
imin: imin(a;b)
, 
uimplies: b supposing a
, 
has-value: (a)↓
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
prop: ℙ
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
assert: ↑b
, 
false: False
, 
not: ¬A
Lemmas referenced : 
value-type-has-value, 
int-value-type, 
le_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_le_int, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
le_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
hypothesis, 
intEquality, 
sqequalRule, 
sqequalHypSubstitution, 
isect_memberEquality, 
isectElimination, 
thin, 
hypothesisEquality, 
axiomEquality, 
because_Cache, 
extract_by_obid, 
independent_isectElimination, 
callbyvalueReduce, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
dependent_pairFormation, 
promote_hyp, 
dependent_functionElimination, 
instantiate, 
cumulativity, 
independent_functionElimination, 
voidElimination
Latex:
\mforall{}[x,y:\mBbbZ{}].    (imin(x;imax(x;y))  =  x)
Date html generated:
2017_04_14-AM-09_14_31
Last ObjectModification:
2017_02_27-PM-03_51_54
Theory : int_2
Home
Index