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1. p k
φ(p k ) (note that it can be the empty set
as well);
2. nil
→∅
, and a
→∅
for each a
Act ;
3. a.t
→{
(a,a i .t i )
|
(a i ,t i )
φ # (t)
}
if
|
φ # (t)
|≥
1
;∅
otherwise;
1 i n φ # (t i ) .
Let us show that this mapping satisfies the equation φ # =
n (t 1 ,...,t n )
4.
F(μ X )
λ
T P X T P (φ) ,
i.e., the diagram
1. In the case t
=
p k
X , F(μ X )
λ
T P X T P (φ)(p k )
=
F(μ X )
λ
T P X (φ(p k ))
where S
S be-
cause in S all terms are fattened (they are the variables). While φ # (p k )
=
φ(p k )
F(
T P X) , so that F(μ X )
λ
T P X (S)
=
F(μ X )(S)
=
=
S .
2. For any a
φ(p k )
=
Act (or nil ),
λ T P X T P (φ)(a)
=
=
=∅=
F(μ X )
F(μ X )
λ T P X (a)
F(μ X )(
)
φ # (a).
Let us show that this equation is valid by structural induction on the length of
terms (considered by a number of operators contained in a term), and assume
that it holds for the terms t,t 1 ,...,t n , n
1, of the length m . Then we consider
a term with the length greater than m , that is, one of the following cases:
2.1. The case of a term a.t . Then
λ T P X T P (φ)(a.t)
F(μ X )
λ T P X a.
T P (φ)(t)
=
F(μ X )
F(μ X ) (a,a k .t k )
λ T P X T P (φ)(t)
=
|
(a k ,t k )
= a,a k .F(μ X )(t k ) |
T P X T P (φ)(t)
(a k ,t k )
λ
= a,a k .t k | a k ,t k
F(μ X ) λ
T P X T P (φ)(t)
= a,a k .t k | a k ,t k
φ # (t) =
φ # (a.t).
If
T P (φ)(t)
=∅
(for example, t is a constant or a variable p k such that
), we obtain analogous result.
2.2. The case of a term
φ(p k )
=∅
n (t 1 ,...,t n ) . Then
T P X T P (φ)
n (t 1 ,...,t n )
F(μ X )
λ
T P X
n T P (φ)(t 1 ),...,
T P (φ)(t n )
=
F(μ X )
λ
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