Solution found with 19 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (0,2) (2,1) 
  and ends at (0,2)
Line 14 starts at (0,2)
  goes through (0,2) (1,3) 
  and ends at (1,3)
Line 15 starts at (1,3)
  goes through (0,0) (1,3) 
  and ends at (0,0)
Line 16 starts at (0,0)
  goes through (0,0) (2,3) 
  and ends at (4,6)
Line 17 starts at (4,6)
  goes through (1,0) (2,2) 
  and ends at (1,0)
Line 18 starts at (1,0)
  goes through (1,0) (2,0) (3,0) 
  and ends at (3,0)
Line 19 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 19 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (0,2) (2,1) 
  and ends at (0,2)
Line 14 starts at (0,2)
  goes through (0,2) (1,3) 
  and ends at (1,3)
Line 15 starts at (1,3)
  goes through (0,0) (1,3) 
  and ends at (0,0)
Line 16 starts at (0,0)
  goes through (0,0) (3,2) 
  and ends at (9/2,3)
Line 17 starts at (9/2,3)
  goes through (1,3) (2,3) (3,3) 
  and ends at (1,3)
Line 18 starts at (1,3)
  goes through (1,3) (2,2) (3,1) 
  and ends at (4,0)
Line 19 starts at (4,0)
  goes through (0,0) (1,0) (2,0) (3,0) 
  and ends at (0,0)

Solution found with 18 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (0,2) (2,1) 
  and ends at (0,2)
Line 14 starts at (0,2)
  goes through (0,2) (1,3) 
  and ends at (1,3)
Line 15 starts at (1,3)
  goes through (1,3) (2,0) 
  and ends at (2,0)
Line 16 starts at (2,0)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,3)
Line 17 starts at (2,3)
  goes through (2,3) (3,0) 
  and ends at (3,0)
Line 18 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 18 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (0,2) (2,1) 
  and ends at (0,2)
Line 14 starts at (0,2)
  goes through (0,2) (1,3) 
  and ends at (4,6)
Line 15 starts at (4,6)
  goes through (1,0) (2,2) 
  and ends at (1,0)
Line 16 starts at (1,0)
  goes through (1,0) (2,0) (3,0) 
  and ends at (3,0)
Line 17 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,9/2)
Line 18 starts at (3,9/2)
  goes through (0,0) (2,3) 
  and ends at (0,0)

Solution found with 17 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (0,2) (2,1) 
  and ends at (0,2)
Line 14 starts at (0,2)
  goes through (0,2) (1,3) 
  and ends at (2,4)
Line 15 starts at (2,4)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,0)
Line 16 starts at (2,0)
  goes through (2,0) (3,0) 
  and ends at (3,0)
Line 17 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 17 lines.
This solution is reentrant.
Line 1 starts at (0,-4)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (0,2) (2,1) 
  and ends at (0,2)
Line 14 starts at (0,2)
  goes through (0,2) (3,0) 
  and ends at (6,-2)
Line 15 starts at (6,-2)
  goes through (1,3) (2,2) (3,1) 
  and ends at (1,3)
Line 16 starts at (1,3)
  goes through (1,3) (2,3) (3,3) 
  and ends at (7/2,3)
Line 17 starts at (7/2,3)
  goes through (2,0) (3,2) 
  and ends at (0,-4)

Solution found with 16 lines.
Line 1 starts at (0,-4)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (2,1) (2,2) (2,3) 
  and ends at (2,5)
Line 14 starts at (2,5)
  goes through (0,1) (1,3) 
  and ends at (0,1)
Line 15 starts at (0,1)
  goes through (0,1) (2,0) 
  and ends at (3,-1/2)
Line 16 starts at (3,-1/2)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 16 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (-2,-1)
Line 12 starts at (-2,-1)
  goes through (0,0) (2,1) 
  and ends at (2,1)
Line 13 starts at (2,1)
  goes through (2,1) (3,2) 
  and ends at (4,3)
Line 14 starts at (4,3)
  goes through (1,3) (2,3) (3,3) 
  and ends at (1,3)
Line 15 starts at (1,3)
  goes through (1,3) (2,2) (3,1) 
  and ends at (4,0)
Line 16 starts at (4,0)
  goes through (0,0) (1,0) (2,0) (3,0) 
  and ends at (0,0)

Solution found with 15 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (0,1) (1,2) 
  and ends at (0,1)
Line 12 starts at (0,1)
  goes through (0,1) (1,3) 
  and ends at (2,5)
Line 13 starts at (2,5)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,0)
Line 14 starts at (2,0)
  goes through (2,0) (3,0) 
  and ends at (3,0)
Line 15 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 15 lines.
This solution is reentrant.
Line 1 starts at (0,-1)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (1,2)
Line 11 starts at (1,2)
  goes through (1,0) (1,1) (1,2) 
  and ends at (1,0)
Line 12 starts at (1,0)
  goes through (1,0) (2,0) (3,0) 
  and ends at (4,0)
Line 13 starts at (4,0)
  goes through (1,3) (2,2) (3,1) 
  and ends at (1,3)
Line 14 starts at (1,3)
  goes through (1,3) (2,3) (3,3) 
  and ends at (4,3)
Line 15 starts at (4,3)
  goes through (1,0) (2,1) (3,2) 
  and ends at (0,-1)

Solution found with 14 lines.
Line 1 starts at (0,-1)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (4/3,8/3)
Line 11 starts at (4/3,8/3)
  goes through (2,2) (3,1) 
  and ends at (4,0)
Line 12 starts at (4,0)
  goes through (1,0) (2,0) (3,0) 
  and ends at (1,0)
Line 13 starts at (1,0)
  goes through (1,0) (2,1) (3,2) 
  and ends at (4,3)
Line 14 starts at (4,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (0,3)

Solution found with 14 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,0) (0,1) (0,2) (0,3) 
  and ends at (0,0)
Line 10 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (2,4)
Line 11 starts at (2,4)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,0)
Line 12 starts at (2,0)
  goes through (2,0) (3,0) 
  and ends at (3,0)
Line 13 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,9)
Line 14 starts at (3,9)
  goes through (0,0) (1,3) 
  and ends at (0,0)

Solution found with 13 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,3) (1,1) 
  and ends at (2,-1)
Line 10 starts at (2,-1)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,4)
Line 11 starts at (2,4)
  goes through (0,0) (1,2) 
  and ends at (0,0)
Line 12 starts at (0,0)
  goes through (0,0) (1,3) 
  and ends at (3,9)
Line 13 starts at (3,9)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,0)

Solution found with 13 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (0,3) (1,0) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,3) (1,2) (2,1) 
  and ends at (2,1)
Line 10 starts at (2,1)
  goes through (2,1) (3,2) 
  and ends at (4,3)
Line 11 starts at (4,3)
  goes through (1,3) (2,3) (3,3) 
  and ends at (1,3)
Line 12 starts at (1,3)
  goes through (1,3) (2,2) (3,1) 
  and ends at (4,0)
Line 13 starts at (4,0)
  goes through (0,0) (1,0) (2,0) (3,0) 
  and ends at (0,0)

Solution found with 12 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (1,0) (2,0) 
  and ends at (2,0)
Line 9 starts at (2,0)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,3)
Line 10 starts at (2,3)
  goes through (0,3) (1,3) (2,3) 
  and ends at (0,3)
Line 11 starts at (0,3)
  goes through (0,3) (1,2) (2,1) (3,0) 
  and ends at (3,0)
Line 12 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 12 lines.
This solution is reentrant.
Line 1 starts at (0,-6)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (1,0)
Line 8 starts at (1,0)
  goes through (1,0) (2,2) 
  and ends at (5/2,3)
Line 9 starts at (5/2,3)
  goes through (0,3) (1,3) (2,3) 
  and ends at (0,3)
Line 10 starts at (0,3)
  goes through (0,3) (1,2) (2,1) (3,0) 
  and ends at (3,0)
Line 11 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)
Line 12 starts at (3,3)
  goes through (2,0) (3,3) 
  and ends at (0,-6)

Solution found with 11 lines.
Line 1 starts at (0,-6)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,0) 
  and ends at (2,-2)
Line 8 starts at (2,-2)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,3)
Line 9 starts at (2,3)
  goes through (0,3) (1,3) (2,3) 
  and ends at (0,3)
Line 10 starts at (0,3)
  goes through (0,3) (1,2) (2,1) (3,0) 
  and ends at (3,0)
Line 11 starts at (3,0)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)

Solution found with 11 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (0,2) 
  and ends at (0,2)
Line 7 starts at (0,2)
  goes through (0,2) (1,2) (2,2) (3,2) 
  and ends at (3,2)
Line 8 starts at (3,2)
  goes through (3,0) (3,1) (3,2) 
  and ends at (3,-1/2)
Line 9 starts at (3,-1/2)
  goes through (0,1) (2,0) 
  and ends at (-4,3)
Line 10 starts at (-4,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (6,3)
Line 11 starts at (6,3)
  goes through (0,0) (2,1) 
  and ends at (0,0)

Solution found with 10 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,1) (1,1) 
  and ends at (0,1)
Line 6 starts at (0,1)
  goes through (0,1) (1,2) (2,3) 
  and ends at (2,3)
Line 7 starts at (2,3)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,-2)
Line 8 starts at (2,-2)
  goes through (0,2) (1,0) 
  and ends at (-1/2,3)
Line 9 starts at (-1/2,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (3,3)
Line 10 starts at (3,3)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,0)

Solution found with 10 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) 
  and ends at (1,1)
Line 5 starts at (1,1)
  goes through (0,2) (1,1) 
  and ends at (0,2)
Line 6 starts at (0,2)
  goes through (0,2) (1,2) (2,2) (3,2) 
  and ends at (3,2)
Line 7 starts at (3,2)
  goes through (3,0) (3,1) (3,2) 
  and ends at (3,-1/2)
Line 8 starts at (3,-1/2)
  goes through (0,1) (2,0) 
  and ends at (-4,3)
Line 9 starts at (-4,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (6,3)
Line 10 starts at (6,3)
  goes through (0,0) (2,1) 
  and ends at (0,0)

Solution found with 9 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) (2,2) 
  and ends at (2,2)
Line 5 starts at (2,2)
  goes through (0,3) (2,2) 
  and ends at (-2,4)
Line 6 starts at (-2,4)
  goes through (0,2) (1,1) (2,0) 
  and ends at (3,-1)
Line 7 starts at (3,-1)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)
Line 8 starts at (3,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (0,3)
Line 9 starts at (0,3)
  goes through (0,3) (1,2) (2,1) (3,0) 
  and ends at (3,0)

Solution found with 9 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,1) (2,2) (3,3) 
  and ends at (4,4)
Line 5 starts at (4,4)
  goes through (0,2) (2,3) 
  and ends at (-12,-4)
Line 6 starts at (-12,-4)
  goes through (0,0) (3,1) 
  and ends at (21/5,7/5)
Line 7 starts at (21/5,7/5)
  goes through (1,3) (3,2) 
  and ends at (-1,4)
Line 8 starts at (-1,4)
  goes through (0,3) (1,2) (2,1) (3,0) 
  and ends at (3,0)
Line 9 starts at (3,0)
  goes through (0,0) (1,0) (2,0) (3,0) 
  and ends at (0,0)

Solution found with 8 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,0) (1,0) 
  and ends at (0,0)
Line 4 starts at (0,0)
  goes through (0,0) (1,2) 
  and ends at (2,4)
Line 5 starts at (2,4)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,0)
Line 6 starts at (2,0)
  goes through (0,2) (1,1) (2,0) 
  and ends at (-1,3)
Line 7 starts at (-1,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (3,3)
Line 8 starts at (3,3)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,0)

Solution found with 8 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (0,2) (1,0) 
  and ends at (0,2)
Line 4 starts at (0,2)
  goes through (0,2) (1,2) (2,2) (3,2) 
  and ends at (3,2)
Line 5 starts at (3,2)
  goes through (3,0) (3,1) (3,2) 
  and ends at (3,-1)
Line 6 starts at (3,-1)
  goes through (0,2) (1,1) (2,0) 
  and ends at (-1,3)
Line 7 starts at (-1,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (6,3)
Line 8 starts at (6,3)
  goes through (0,0) (2,1) 
  and ends at (0,0)

Solution found with 7 lines.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (1,0)
Line 3 starts at (1,0)
  goes through (1,0) (2,1) (3,2) 
  and ends at (3,2)
Line 4 starts at (3,2)
  goes through (0,2) (1,2) (2,2) (3,2) 
  and ends at (0,2)
Line 5 starts at (0,2)
  goes through (0,2) (1,1) (2,0) 
  and ends at (3,-1)
Line 6 starts at (3,-1)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,3)
Line 7 starts at (3,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (0,3)

Solution found with 7 lines.
This solution is reentrant.
Line 1 starts at (0,0)
  goes through (0,0) (0,1) 
  and ends at (0,1)
Line 2 starts at (0,1)
  goes through (0,1) (1,0) 
  and ends at (2,-1)
Line 3 starts at (2,-1)
  goes through (2,0) (2,1) (2,2) (2,3) 
  and ends at (2,3)
Line 4 starts at (2,3)
  goes through (0,3) (1,3) (2,3) 
  and ends at (-1,3)
Line 5 starts at (-1,3)
  goes through (0,2) (1,1) (2,0) 
  and ends at (3,-1)
Line 6 starts at (3,-1)
  goes through (3,0) (3,1) (3,2) (3,3) 
  and ends at (3,6)
Line 7 starts at (3,6)
  goes through (0,0) (1,2) 
  and ends at (0,0)

Solution found with 6 lines.
This solution is reentrant.
Line 1 starts at (0,-1)
  goes through (0,0) (0,1) (0,2) 
  and ends at (0,2)
Line 2 starts at (0,2)
  goes through (0,2) (1,2) (2,2) (3,2) 
  and ends at (3,2)
Line 3 starts at (3,2)
  goes through (3,0) (3,1) (3,2) 
  and ends at (3,-1)
Line 4 starts at (3,-1)
  goes through (0,2) (1,1) (2,0) 
  and ends at (-1,3)
Line 5 starts at (-1,3)
  goes through (0,3) (1,3) (2,3) (3,3) 
  and ends at (4,3)
Line 6 starts at (4,3)
  goes through (1,0) (2,1) (3,2) 
  and ends at (0,-1)

1 solutions found.