Difference between revisions of "Alloy"

(Created page with "Category:User Manual As of version 1.8 ProB provides support to load [http://alloy.mit.edu/alloy/ Alloy] models. The Alloy models are translated to B machines by a [http...")
 
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This work and web page is still experimental.
 
This work and web page is still experimental.
 +
 +
The work is based on a translation of the specification language Alloy to classical B. The translation allows us to load Alloy models into ProB in order to find solutions to the model's constraints.
 +
The translation is syntax-directed and closely follows the Alloy grammar. Each Alloy construct is translated into a semantically equivalent component of the B language. In addition to basic Alloy constructs, our approach supports integers and orderings.
  
 
== Installation ==
 
== Installation ==
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Clone or download [https://github.com/hhu-stups/alloy2b Alloy2B project on Github].
 
Clone or download [https://github.com/hhu-stups/alloy2b Alloy2B project on Github].
 
Make jar file (gradle build) and put resulting alloy2b-*.jar file into ProB's lib folder.
 
Make jar file (gradle build) and put resulting alloy2b-*.jar file into ProB's lib folder.
 +
 +
== Examples ==
 +
 +
 +
=== N-Queens ===
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<pre>
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module queens
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open util/integer
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sig queen { x:Int, x':Int, y:Int } {
 +
    x >= 1
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    y >= 1
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    x <= #queen
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    y <= #queen
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    x' >=1
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    x' <= #queen
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    x' = minus[plus[#queen,1],x]
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}
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fact { all q:queen, q':(queen-q) {
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    ! q.x = q'.x
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    ! q.y = q'.y
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    ! plus[q.x,q.y] = plus[q'.x,q'.y]
 +
    ! plus[q.x',q.y] = plus[q'.x',q'.y]
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}}
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pred show {}
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run show for exactly 4 queen, 5 int
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</pre>
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 +
is translated to:
 +
 +
<pre>
 +
/*@ generated */
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MACHINE queens
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SETS queen_
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CONSTANTS x_queen, x__queen, y_queen
 +
DEFINITIONS
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    show_ ==  1=1 ;
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    SET_PREF_MAXINT == 15 ; SET_PREF_MININT == -16
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PROPERTIES
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    (!(q_, q__).({q_} <: queen_ & {q__} <: (queen_ - {q_}) =>
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    (not((x_queen(q_) = x_queen(q__)))) & (not((y_queen(q_) = y_queen(q__))))
 +
    & (not(((x_queen(q_) + y_queen(q_)) = (x_queen(q__) + y_queen(q__)))))
 +
    & (not(((x__queen(q_) + y_queen(q_)) = (x__queen(q__) + y_queen(q__))))))) &
 +
    card(queen_) = 4 &
 +
    /* from signature declaration */ !(this_).({this_} <: queen_ =>
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    ((x_queen(this_) >= 1)) & ((y_queen(this_) >= 1))
 +
    & ((x_queen(this_) <= card(queen_)))
 +
    & ((y_queen(this_) <= card(queen_)))
 +
    & ((x__queen(this_) >= 1)) & ((x__queen(this_) <= card(queen_)))
 +
    & ((x__queen(this_) = ((card(queen_) + 1) - x_queen(this_))))) &
 +
    x_queen : queen_ --> INT &
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    x__queen : queen_ --> INT &
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    y_queen : queen_ --> INT
 +
OPERATIONS
 +
    run_show = PRE show_ THEN skip END
 +
END
 +
</pre>

Revision as of 09:22, 7 February 2018


As of version 1.8 ProB provides support to load Alloy models. The Alloy models are translated to B machines by a Java frontend.

This work and web page is still experimental.

The work is based on a translation of the specification language Alloy to classical B. The translation allows us to load Alloy models into ProB in order to find solutions to the model's constraints. The translation is syntax-directed and closely follows the Alloy grammar. Each Alloy construct is translated into a semantically equivalent component of the B language. In addition to basic Alloy constructs, our approach supports integers and orderings.

Installation

Clone or download Alloy2B project on Github. Make jar file (gradle build) and put resulting alloy2b-*.jar file into ProB's lib folder.

Examples

N-Queens

module queens
open util/integer
sig queen { x:Int, x':Int, y:Int } {
    x >= 1
    y >= 1
    x <= #queen
    y <= #queen
    x' >=1
    x' <= #queen
    x' = minus[plus[#queen,1],x]
}
fact { all q:queen, q':(queen-q) {
    ! q.x = q'.x
    ! q.y = q'.y
    ! plus[q.x,q.y] = plus[q'.x,q'.y]
    ! plus[q.x',q.y] = plus[q'.x',q'.y]
}}
pred show {}
run show for exactly 4 queen, 5 int

is translated to:

/*@ generated */
MACHINE queens
SETS queen_
CONSTANTS x_queen, x__queen, y_queen
DEFINITIONS
    show_ ==   1=1 ;
    SET_PREF_MAXINT == 15 ; SET_PREF_MININT == -16
PROPERTIES
    (!(q_, q__).({q_} <: queen_ & {q__} <: (queen_ - {q_}) => 
    		(not((x_queen(q_) = x_queen(q__)))) & (not((y_queen(q_) = y_queen(q__)))) 
    		& (not(((x_queen(q_) + y_queen(q_)) = (x_queen(q__) + y_queen(q__)))))
    		& (not(((x__queen(q_) + y_queen(q_)) = (x__queen(q__) + y_queen(q__))))))) &
    card(queen_) = 4 &
    /* from signature declaration */ !(this_).({this_} <: queen_ => 
    		((x_queen(this_) >= 1)) & ((y_queen(this_) >= 1))
    		& ((x_queen(this_) <= card(queen_)))
    		& ((y_queen(this_) <= card(queen_)))
    		& ((x__queen(this_) >= 1)) & ((x__queen(this_) <= card(queen_)))
    		& ((x__queen(this_) = ((card(queen_) + 1) - x_queen(this_))))) &
    x_queen : queen_ --> INT &
    x__queen : queen_ --> INT &
    y_queen : queen_ --> INT
OPERATIONS
    run_show = PRE show_ THEN skip END
END