! Document name: half_grid_2

!1/2_grid_2  11.07.1989.
!internal macro: -

pars a,b,frame width

let d=1"

let z=a/2-c
let f=b-c

let m=1.414

poly_ 5,
0,c,1,
d/m,c,1,
0.707*z+d/m/2,0.707*f-d/m/2,0,
0.707*z-d/m/2,0.707*f+d/m/2,1,
0,d/m+c,1

poly_ 5,
0,c,1,
-d/m,c,1,
-0.707*z-d/m/2,0.707*f-d/m/2,0,
-0.707*z+d/m/2,0.707*f+d/m/2,1,
0,d/m+c,1

poly_ 5,
0,d/m+c,0,
d/2,d/m+c+d/2,1,
d/2,b-c,0,
-d/2,b-c,1,
-d/2,d/m+c+d/2,0

del top
end