Ascend FD-23R Manual de usuario descargar pdf (Pagina 24)

12 CHAPTER 1. The TOY(FD) System

TOY(FD)> domain [X,Y] 1 10, X #> Y

yes

Y in 1..9

X in 2..10

Elapsed time: 0 ms.

(#∗)/2, (#+)/2, (#−)/2, (#/)/2

• Type declaration:

(#∗) :: int → int → int

(#+) :: int → int → int

(#−) :: int → int → int

(#/) :: int → int → int

• Deﬁnition: ’#Op A B’, also written in inﬁx notation as ’A #Op B’, where Op

∈ {∗, +, −, /} imposes the constraint ’A #Op B’ and returns true if it is entailed.

• Remarks: Inﬁx notation allowed.

• Priorities:

infixr 90 #*, #/ (infix, right-associative)

infixl 50 #+, #- (infix, left-associative)

• Example at the TOY(FD) command level:

Next goal returns true and constrains X, Y and Z to have values in the intervals

[1,10], [1,10] and [1,100] respectively.

TOY(FD)> domain [X,Y] 1 10, X #* Y #= Z

yes

Z in 1..100

Y in 1..10

X in 1..10

Elapsed time: 0 ms.

1.4.4 Arithmetic Constraints

The following constraints express a relation between a sum or scalar product and a

value, using a dedicated algorithm that avoids creating any temporary variables hold-

ing intermediate values.

sum/3

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 80 81

Sin comentarios

Ascend FD-23R Manual de usuario Pagina 24