Nuprl Lemma : sign_wf
∀[x:ℤ]. (sign(x) ∈ ℤ)
Proof
Definitions occuring in Statement :
sign: sign(x),
uall: ∀[x:A]. B[x],
member: t ∈ T,
int: ℤ
Definitions unfolded in proof :
sign: sign(x),
uall: ∀[x:A]. B[x],
member: t ∈ T
Lemmas referenced :
ifthenelse_wf,
le_int_wf
Rules used in proof :
sqequalSubstitution,
sqequalRule,
sqequalReflexivity,
sqequalTransitivity,
computationStep,
isect_memberFormation,
introduction,
cut,
lemma_by_obid,
sqequalHypSubstitution,
isectElimination,
thin,
natural_numberEquality,
hypothesisEquality,
hypothesis,
intEquality,
minusEquality,
axiomEquality,
equalityTransitivity,
equalitySymmetry
Latex:
\mforall{}[x:\mBbbZ{}]. (sign(x) \mmember{} \mBbbZ{})
Date html generated:
2016_05_14-PM-04_28_09
Last ObjectModification:
2015_12_26-PM-08_04_47
Theory : num_thy_1
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