       10 // TAN() test program
       20 //
       30 // The number 33 was chosen so that TAN(f) is never infinite :)
       40 FOR f:=0 TO 2*PI STEP PI/33 DO
       50   d:=TAN(f)-SIN(f)/COS(f)
       60   SYS assert, ABS(d)<0.00000001
       70 ENDFOR f
       80 PRINT "Ok"
