       10 // PROC test program
       20 //
       30 aa#:=1; bb:=2.5; cc$:="Hallo"
       40 aap(aa#, bb, cc$)
       50 SYS assert, aa#=1 AND bb=2.5 AND cc$="Hallo"
       60 PRINT "Ok"
       70 //
       80 PROC aap(a#, b, c$)
       90   SYS assert, a#=1 AND b=2.5 AND c$="Hallo"
      100   a#:=2; b:=5.2; c$:="Hello"
      110 ENDPROC aap
