Nuprl Lemma : equal-bnot
∀[x,y:𝔹].  uiff(x = ¬by;¬x = y)
Proof
Definitions occuring in Statement : 
bnot: ¬bb
, 
bool: 𝔹
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
not: ¬A
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uall: ∀[x:A]. B[x]
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
bnot: ¬bb
, 
ifthenelse: if b then t else f fi 
, 
not: ¬A
, 
false: False
, 
prop: ℙ
, 
assert: ↑b
, 
bfalse: ff
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
decidable: Dec(P)
Lemmas referenced : 
eqtt_to_assert, 
btrue_neq_bfalse, 
equal-wf-T-base, 
bool_wf, 
iff_imp_equal_bool, 
bfalse_wf, 
assert_elim, 
assert_wf, 
false_wf, 
not_wf, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
assert_witness, 
assert_of_bnot, 
bnot_wf, 
uiff_wf, 
iff_weakening_uiff, 
decidable__assert
Rules used in proof : 
cut, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
hypothesisEquality, 
thin, 
because_Cache, 
lambdaFormation, 
sqequalHypSubstitution, 
unionElimination, 
equalityElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesis, 
productElimination, 
independent_isectElimination, 
sqequalRule, 
independent_pairFormation, 
isect_memberFormation, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
voidElimination, 
baseClosed, 
lambdaEquality, 
dependent_functionElimination, 
addLevel, 
levelHypothesis, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
cumulativity, 
functionEquality, 
independent_pairEquality, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[x,y:\mBbbB{}].    uiff(x  =  \mneg{}\msubb{}y;\mneg{}x  =  y)
Date html generated:
2017_10_01-AM-09_12_43
Last ObjectModification:
2017_07_26-PM-04_48_20
Theory : general
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