Nuprl Lemma : subtype_rel_b-union
∀[A1,B1,A2,B2:Type].  (A1 ⋃ B1) ⊆r (A2 ⋃ B2) supposing (A1 ⊆r A2) ∧ (B1 ⊆r B2)
Proof
Definitions occuring in Statement : 
b-union: A ⋃ B
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
and: P ∧ Q
, 
universe: Type
Definitions unfolded in proof : 
b-union: A ⋃ B
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
and: P ∧ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
prop: ℙ
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
assert: ↑b
, 
false: False
Lemmas referenced : 
subtype_rel_tunion, 
bool_wf, 
ifthenelse_wf, 
eqtt_to_assert, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
subtype_rel_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
productElimination, 
thin, 
extract_by_obid, 
isectElimination, 
hypothesis, 
lambdaEquality, 
instantiate, 
hypothesisEquality, 
universeEquality, 
cumulativity, 
because_Cache, 
independent_isectElimination, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
dependent_pairFormation, 
promote_hyp, 
dependent_functionElimination, 
independent_functionElimination, 
voidElimination, 
equalityTransitivity, 
equalitySymmetry, 
axiomEquality, 
productEquality, 
isect_memberEquality
Latex:
\mforall{}[A1,B1,A2,B2:Type].    (A1  \mcup{}  B1)  \msubseteq{}r  (A2  \mcup{}  B2)  supposing  (A1  \msubseteq{}r  A2)  \mwedge{}  (B1  \msubseteq{}r  B2)
Date html generated:
2017_04_14-AM-07_30_21
Last ObjectModification:
2017_02_27-PM-02_59_05
Theory : bool_1
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