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Commit 312f137e authored by Jean-Christophe Filliâtre's avatar Jean-Christophe Filliâtre
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gallery: some experiments in vstte10_queens to count solutions

parent 20cdf859
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examples/vstte10_queens.mlw
View file @ 312f137e
......@@ -111,4 +111,121 @@ module NQueens
with Solution -> a
end
(** variant: counting solutions (not part of the competition)
TODO: prove soundness i.e. we indeed count the number of solutions *)
use import ref.Refint
let rec count_bt_queens (board: array int) (n: int) (pos: int) : int
variant { n - pos }
requires { length board = n /\ 0 <= pos <= n /\ solution board pos }
ensures { eq_board board (old board) pos }
= 'Init:
if pos = n then
1
else begin
let s = ref 0 in
for i = 0 to n - 1 do
invariant { eq_board board (at board 'Init) pos }
board[pos] <- i;
if check_is_consistent board pos then
s += count_bt_queens board n (pos+1)
done;
!s
end
let count_queens (board: array int) (n: int) : int
requires { length board = n }
ensures { true }
= count_bt_queens board n 0
let test_count_8 () =
let a = Array.make 8 0 in
count_queens a 8
end
(** counting solutions with machine integers *)
module MachineArithmetic
use import ref.Refint
use import mach.array.Array63
use import mach.int.Int63
predicate is_board (board: array int63) (pos: int) =
forall q: int. 0 <= q < pos ->
0 <= to_int board[q] < to_int (length board)
exception MInconsistent int63
let mcheck_is_consistent (board: array int63) (pos: int63)
requires { 0 <= to_int pos < to_int (length board) }
requires { is_board board (to_int pos + 1) }
= try
let rec forloop q (* for q = 0 to pos-1 do *) =
requires { 0 <= to_int q <= to_int pos }
requires { is_board board (to_int pos + 1) }
variant { to_int pos - to_int q }
raises { MInconsistent -> true }
if q < pos then begin
let bq = board[q] in
let bpos = board[pos] in
if bq = bpos then raise (MInconsistent q);
if bq - bpos = pos - q then raise (MInconsistent q);
if bpos - bq = pos - q then raise (MInconsistent q);
forloop (q + of_int 1)
end in
forloop (of_int 0);
True
with MInconsistent _ ->
False
end
use mach.onetime.OneTime as O
(***
let rec mcount_bt_queens (board: array int63) (n: int63) (pos: int63) : O.t
requires { to_int (length board) = to_int n }
requires { 0 <= to_int pos <= to_int n }
requires { is_board board (to_int pos) }
variant { to_int n - to_int pos }
ensures { is_board board (to_int pos) }
=
if eq pos n then
O.succ (O.zero ())
else begin
let s = ref (O.zero ()) in
let rec forloop (i: int63) = (* for i = 0 to n-1 do *)
requires { 0 <= to_int i <= to_int n }
requires { is_board board (to_int pos) }
variant { to_int n - to_int i }
ensures { is_board board (to_int pos) }
if i < n then begin
board[pos] <- i;
if mcheck_is_consistent board pos then
s := O.add !s (mcount_bt_queens board n (pos + of_int 1));
(* let _ = O.add !s (mcount_bt_queens board n (pos + of_int 1))
in (); *)
forloop (i + of_int 1)
end in
forloop (of_int 0);
!s
end
let mcount_queens (board: array int63) (n: int63) : O.t
requires { to_int (length board) = to_int n }
ensures { true }
= mcount_bt_queens board n (of_int 0)
let test_mcount_8 () =
let n = of_int 8 in
let a = Array63.make n (of_int 0) in
mcount_queens a n
***)
end
examples/vstte10_queens/why3session.xml
View file @ 312f137e
......@@ -2,43 +2,149 @@
<!DOCTYPE why3session PUBLIC "-//Why3//proof session v5//EN"
"http://why3.lri.fr/why3session.dtd">
<why3session shape_version="4">
<prover id="0" name="Coq" version="8.4pl4" timelimit="20" memlimit="0"/>
<prover id="0" name="CVC4" version="1.4" timelimit="6" memlimit="1000"/>
<prover id="1" name="CVC3" version="2.4.1" timelimit="20" memlimit="0"/>
<prover id="2" name="Alt-Ergo" version="0.95.1" timelimit="20" memlimit="0"/>
<prover id="3" name="Z3" version="3.2" timelimit="8" memlimit="1000"/>
<prover id="4" name="Alt-Ergo" version="0.95.2" timelimit="5" memlimit="0"/>
<prover id="4" name="Alt-Ergo" version="0.95.2" timelimit="6" memlimit="0"/>
<prover id="5" name="Z3" version="4.3.1" timelimit="6" memlimit="1000"/>
<file name="../vstte10_queens.mlw" expanded="true">
<theory name="NQueens" sum="762623aaf4b051407a7a7e388df720fc" expanded="true">
<goal name="eq_board_set" expanded="true">
<proof prover="4" memlimit="1000"><result status="valid" time="0.00"/></proof>
<theory name="NQueens" sum="05ca6b285c56c769408f7ad47741cffe">
<goal name="eq_board_set">
<proof prover="4" timelimit="5" memlimit="1000"><result status="valid" time="0.00" steps="7"/></proof>
</goal>
<goal name="eq_board_sym" expanded="true">
<proof prover="2"><result status="valid" time="0.01"/></proof>
<goal name="eq_board_sym">
<proof prover="2"><result status="valid" time="0.01" steps="7"/></proof>
</goal>
<goal name="eq_board_trans" expanded="true">
<proof prover="2"><result status="valid" time="0.01"/></proof>
<goal name="eq_board_trans">
<proof prover="2"><result status="valid" time="0.01" steps="10"/></proof>
</goal>
<goal name="eq_board_extension" expanded="true">
<proof prover="2"><result status="valid" time="0.01"/></proof>
<goal name="eq_board_extension">
<proof prover="2"><result status="valid" time="0.01" steps="9"/></proof>
</goal>
<goal name="consistent_row_eq" expanded="true">
<proof prover="2"><result status="valid" time="0.06"/></proof>
<goal name="consistent_row_eq">
<proof prover="2"><result status="valid" time="0.06" steps="37"/></proof>
</goal>
<goal name="WP_parameter check_is_consistent" expl="VC for check_is_consistent" expanded="true">
<goal name="WP_parameter check_is_consistent" expl="VC for check_is_consistent">
<proof prover="1"><result status="valid" time="0.02"/></proof>
</goal>
<goal name="solution_eq_board" expanded="true">
<proof prover="0" edited="vstte10_queens_NQueens_solution_eq_board_1.v"><result status="valid" time="1.31"/></proof>
<goal name="solution_eq_board">
<proof prover="3"><result status="valid" time="0.06"/></proof>
</goal>
<goal name="WP_parameter bt_queens" expl="VC for bt_queens" expanded="true">
<proof prover="1"><result status="valid" time="1.46"/></proof>
<goal name="WP_parameter bt_queens" expl="VC for bt_queens">
<proof prover="1"><result status="valid" time="1.21"/></proof>
</goal>
<goal name="WP_parameter queens" expl="VC for queens" expanded="true">
<proof prover="4" timelimit="20"><result status="valid" time="0.02"/></proof>
<goal name="WP_parameter queens" expl="VC for queens">
<proof prover="4" timelimit="20"><result status="valid" time="0.02" steps="21"/></proof>
</goal>
<goal name="WP_parameter test8" expl="VC for test8" expanded="true">
<proof prover="4" memlimit="1000"><result status="valid" time="0.01"/></proof>
<goal name="WP_parameter test8" expl="VC for test8">
<proof prover="4" timelimit="5" memlimit="1000"><result status="valid" time="0.01" steps="0"/></proof>
</goal>
<goal name="WP_parameter count_bt_queens" expl="VC for count_bt_queens">
<proof prover="5"><result status="valid" time="0.06"/></proof>
</goal>
<goal name="WP_parameter count_queens" expl="VC for count_queens">
<proof prover="4" memlimit="1000"><result status="valid" time="0.01" steps="8"/></proof>
</goal>
<goal name="WP_parameter test_count_8" expl="VC for test_count_8">
<proof prover="4" memlimit="1000"><result status="valid" time="0.01" steps="0"/></proof>
</goal>
</theory>
<theory name="MachineArithmetic" sum="0500018a9f9265efb1b389c414cb9813" expanded="true">
<goal name="WP_parameter mcheck_is_consistent" expl="VC for mcheck_is_consistent" expanded="true">
<proof prover="0"><result status="valid" time="0.27"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens" expl="VC for mcount_bt_queens">
<transf name="split_goal_wp">
<goal name="WP_parameter mcount_bt_queens.1" expl="1. postcondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="10"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.2" expl="2. index in array bounds">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="15"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.3" expl="3. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="17"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.4" expl="4. precondition">
<proof prover="0"><result status="valid" time="0.05"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.5" expl="5. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="20"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.6" expl="6. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.04" steps="47"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.7" expl="7. variant decrease">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="23"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.8" expl="8. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="23"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.9" expl="9. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="23"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.10" expl="10. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.01" steps="23"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.11" expl="11. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="28"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.12" expl="12. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.15" steps="62"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.13" expl="13. variant decrease">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="31"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.14" expl="14. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="31"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.15" expl="15. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.48" steps="81"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.16" expl="16. postcondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="35"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.17" expl="17. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.01" steps="20"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.18" expl="18. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.08" steps="47"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.19" expl="19. variant decrease">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="23"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.20" expl="20. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="23"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.21" expl="21. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.23" steps="65"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.22" expl="22. postcondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="27"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.23" expl="23. postcondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.01" steps="15"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.24" expl="24. integer overflow">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="11"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.25" expl="25. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="12"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.26" expl="26. precondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="12"/></proof>
</goal>
<goal name="WP_parameter mcount_bt_queens.27" expl="27. postcondition">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="15"/></proof>
</goal>
</transf>
</goal>
<goal name="WP_parameter mcount_queens" expl="VC for mcount_queens">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="14"/></proof>
</goal>
<goal name="WP_parameter test_mcount_8" expl="VC for test_mcount_8">
<proof prover="4" memlimit="1000"><result status="valid" time="0.02" steps="10"/></proof>
<proof prover="5"><result status="valid" time="0.01"/></proof>
</goal>
</theory>
</file>
......
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