Nuprl Lemma : union-Leibniz-type
∀A,B:Type.  (Leibniz-type{i:l}(A) 
⇒ Leibniz-type{i:l}(B) 
⇒ Leibniz-type{i:l}(A + B))
Proof
Definitions occuring in Statement : 
Leibniz-type: Leibniz-type{i:l}(T)
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
union: left + right
, 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
Leibniz-type: Leibniz-type{i:l}(T)
, 
exists: ∃x:A. B[x]
, 
and: P ∧ Q
, 
member: t ∈ T
, 
or: P ∨ Q
, 
true: True
, 
subtype_rel: A ⊆r B
, 
iff: P 
⇐⇒ Q
, 
not: ¬A
, 
false: False
, 
rev_implies: P 
⇐ Q
, 
isl: isl(x)
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
guard: {T}
Lemmas referenced : 
true_wf, 
istype-true, 
istype-void, 
btrue_wf, 
bfalse_wf, 
btrue_neq_bfalse, 
subtype_rel_self, 
Leibniz-type_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
sqequalHypSubstitution, 
productElimination, 
thin, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
cut, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
inhabitedIsType, 
unionElimination, 
sqequalRule, 
applyEquality, 
introduction, 
extract_by_obid, 
equalityIstype, 
dependent_functionElimination, 
independent_functionElimination, 
unionIsType, 
universeIsType, 
independent_pairFormation, 
inlFormation_alt, 
natural_numberEquality, 
inrFormation_alt, 
because_Cache, 
applyLambdaEquality, 
promote_hyp, 
voidElimination, 
inlEquality_alt, 
functionIsType, 
dependent_set_memberEquality_alt, 
productIsType, 
setElimination, 
rename, 
inrEquality_alt, 
instantiate, 
isectElimination, 
cumulativity, 
universeEquality
Latex:
\mforall{}A,B:Type.    (Leibniz-type\{i:l\}(A)  {}\mRightarrow{}  Leibniz-type\{i:l\}(B)  {}\mRightarrow{}  Leibniz-type\{i:l\}(A  +  B))
Date html generated:
2019_10_31-AM-07_25_59
Last ObjectModification:
2019_09_19-PM-06_50_43
Theory : constructive!algebra
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