Copyright | (c) Levent Erkok |
---|---|
License | BSD3 |
Maintainer | erkokl@gmail.com |
Stability | experimental |
Safe Haskell | None |
Language | Haskell2010 |
When we would like to find all solutions to a problem, we can query the
solver repeatedly, telling it to give us a new model each time. SBV already
provides allSat
that precisely does this. However, this example demonstrates
how the query mode can be used to achieve the same, and can also incorporate
extra conditions with easy as we walk through solutions.
Documentation
goodSum :: Symbolic [(Integer, Integer)] Source #
Find all solutions to x + y .== 10
for positive x
and y
, but at each
iteration we would like to ensure that the value of x
we get is at least twice as large as
the previous one. This is rather silly, but demonstrates how we can dynamically
query the result and put in new constraints based on those.
Run the query. We have:
>>>
demo
Starting the all-sat engine! Iteration: 1 Current solution is: (0,10) Iteration: 2 Current solution is: (1,9) Iteration: 3 Current solution is: (2,8) Iteration: 4 Current solution is: (4,6) Iteration: 5 Current solution is: (8,2) Iteration: 6 No other solution! [(0,10),(1,9),(2,8),(4,6),(8,2)]