.PS
# Logic.m4
log_init(svg_font(sans-serif,11bp__))
xgap = 0.5
[ dmov = 0.4
{  {AND_gate ;  "`AND_gate'" ljust at last [].w + (xgap,0)}
   move down dmov; right_
   {OR_gate ;  "`OR_gate'" ljust at last [].w + (xgap,0)}
   move down dmov; right_
   {BUFFER_gate ;  "`BUFFER_gate'" ljust at last [].w + (xgap,0)}
   move down dmov; right_
   {XOR_gate ;  "`XOR_gate'" ljust at last [].w + (xgap,0)}
   }

xgap = 0.65
   move right_ 2
{  { NAND_gate ;  "`NAND_gate'" ljust at last [].w + (xgap,0) }
   move down dmov; right_
   {  Gate: NOR_gate(3)
   "`NOR_gate(3)'" ljust at last [].w + (xgap,0)
   thinlines_
   spline <- from Gate.Out right arrowht*2.0 \
    then up 0.15 then right 0.05
     "`Out'" ljust
   spline <- from Gate.N_Out down arrowht*2.0 \
     then right 0.1+arrowht*1.5+NOT_rad down 0.15-arrowht*2.0
     "`N_Out'" ljust
   for_(1,3,1,
     `arrow <- left 0.2 down 0.05 from Gate.In`'m4x
     "In`'m4x" rjust at Here+(0,(2-m4x)*0.02)')
   }
   thicklines_
   move down dmov; right_
  {  NOT_gate ;  "`NOT_gate'" ljust at last [].w + (xgap,0) }
   move down dmov; right_
  {  NXOR_gate ;  "`NXOR_gate'" ljust at last [].w + (xgap,0)  }
}
   move right_ 2
{ {B: NAND_gate(,B) ;  "`NAND_gate(,B)'" ljust at B.w + (xgap,0)}
   { line invis right 1.8 from last [].se then down 1}
   move down dmov; right_
   move left N_diam*L_unit; right_
  {NOR_gate(3,NB) ;  "`NOR_gate(3,NB)'" ljust at (B.w,last []) + (xgap,0)  }
   move down dmov; right_
  {BOX_gate(PN,N,,,=1)
   "`BOX_gate(PN,N,,,=1)'" ljust at (B.w,last []) + (xgap,0)
   line left 0.15 from last [].In1
   line left 0.15-NOT_rad*2 from last [].In2
   line right 0.15 from last [].Out }
   move down dmov; move right_ N_diam*L_unit
  {BOX_gate(PP,N,,,=)
   "`BOX_gate(PP,N,,,=)'" ljust at (B.w,last []) + (xgap,0)
   line left 0.15 from last [].In1
   line left 0.15 from last [].In2
   line right 0.15 from last [].Out }
}
]
 command "</g>" # end font
.PE