Nuprl Lemma : or-quotient-true-subtype
∀P:ℙ. (⇃(P ∨ (¬P)) ⊆r (⇃(P) ∨ ⇃(¬P)))
Proof
Definitions occuring in Statement : 
quotient: x,y:A//B[x; y]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
or: P ∨ Q
, 
true: True
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
prop: ℙ
, 
uimplies: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
false: False
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
Lemmas referenced : 
disjoint-quotient_subtype, 
not_wf, 
and_wf, 
true_wf, 
equiv_rel_true
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalRule, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
voidElimination, 
lambdaEquality, 
unionEquality, 
universeEquality
Latex:
\mforall{}P:\mBbbP{}.  (\00D9(P  \mvee{}  (\mneg{}P))  \msubseteq{}r  (\00D9(P)  \mvee{}  \00D9(\mneg{}P)))
Date html generated:
2016_05_14-AM-06_08_53
Last ObjectModification:
2015_12_26-AM-11_48_11
Theory : quot_1
Home
Index