Nuprl Lemma : absval_unfold2
∀[x:ℤ]. (|x| ~ if (0) < (x)  then x  else (-x))
Proof
Definitions occuring in Statement : 
absval: |i|
, 
uall: ∀[x:A]. B[x]
, 
less: if (a) < (b)  then c  else d
, 
minus: -n
, 
natural_number: $n
, 
int: ℤ
, 
sqequal: s ~ t
Definitions unfolded in proof : 
absval: |i|
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
has-value: (a)↓
, 
uimplies: b supposing a
Lemmas referenced : 
value-type-has-value, 
int-value-type
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
callbyvalueReduce, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
intEquality, 
independent_isectElimination, 
hypothesis, 
hypothesisEquality, 
sqequalAxiom
Latex:
\mforall{}[x:\mBbbZ{}].  (|x|  \msim{}  if  (0)  <  (x)    then  x    else  (-x))
Date html generated:
2016_05_13-PM-03_33_38
Last ObjectModification:
2015_12_26-AM-09_44_27
Theory : arithmetic
Home
Index