Nuprl Lemma : or-quotient-true
∀P:ℙ. (⇃(P ∨ (¬P)) 
⇒ (⇃(P) ∨ ⇃(¬P)))
Proof
Definitions occuring in Statement : 
quotient: x,y:A//B[x; y]
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
true: True
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
or: P ∨ Q
, 
quotient: x,y:A//B[x; y]
, 
and: P ∧ Q
, 
not: ¬A
, 
false: False
, 
true: True
Lemmas referenced : 
or_wf, 
quotient_wf, 
true_wf, 
equiv_rel_true, 
not_wf, 
quotient-member-eq, 
equal_wf, 
equal-wf-base
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
rename, 
introduction, 
pointwiseFunctionalityForEquality, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
hypothesis, 
because_Cache, 
independent_isectElimination, 
pertypeElimination, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
unionElimination, 
inlEquality, 
dependent_functionElimination, 
independent_functionElimination, 
voidElimination, 
inrEquality, 
natural_numberEquality, 
productEquality, 
universeEquality
Latex:
\mforall{}P:\mBbbP{}.  (\00D9(P  \mvee{}  (\mneg{}P))  {}\mRightarrow{}  (\00D9(P)  \mvee{}  \00D9(\mneg{}P)))
Date html generated:
2016_05_14-AM-06_08_36
Last ObjectModification:
2015_12_26-AM-11_48_17
Theory : quot_1
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