rpicosat

R bindings to the PicoSAT solver release 965 by Armin Biere. The PicoSAT C code is distributed under a MIT style license and is bundled with this package.

Install

Install development version

devtools::install_github("dirkschumacher/rpicosat")

Install stable version from CRAN

install.packages("rpicosat")

API

• picosat_sat can solve a SAT problem. The result is a data.frame + meta data, so you can use it with dplyr et al.
• picosat_solution_status applied to the result of picosat_sat returns either PICOSAT_SATISFIABLE, PICOSAT_UNSATISFIABLE or PICOSAT_UNKNOWN

The following functions can be applied to solutions and make available some statistics generated by the PicoSAT solver:

• picosat_decisions #decisions
• picosat_propagations #propagations
• picosat_seconds seconds spent in the C function picosat_sat
• picosat_variables #variables
• picosat_visits #visits

Example

Suppose we want to test the following formula for satisfiability:

(A ⇒ B)∧(B ⇒ C)∧(C ⇒ A)

This can be formulated as a CNF (conjunctive normal form):

A ∨ B)∧(¬B ∨ C)∧(¬C ∨ A)

In rpicosat the problem is encoded as a list of integer vectors.

formula <- list(
c(-1, 2),
c(-2, 3),
c(-3, 1)
)
library(rpicosat)
res <- picosat_sat(formula)
res
#> Variables: 3
#> Clauses: 3
#> Solver status: PICOSAT_SATISFIABLE

Every result is also a data.frame so you can process the results with packages like dplyr.

as.data.frame(res)
#>   variable value
#> 1        1 FALSE
#> 2        2 FALSE
#> 3        3 FALSE

We can also test for satisfiability if we assume that a certain literal is TRUE or FALSE

picosat_sat(formula, c(1)) # assume A is TRUE
#> Variables: 3
#> Clauses: 3
#> Solver status: PICOSAT_SATISFIABLE
picosat_sat(formula, c(1, -3)) # assume A is TRUE, but C is FALSE
#> Solver status: PICOSAT_UNSATISFIABLE