PROGRAM example ! beginning of main program ! specify initial values and parameters CALL initial(y,x,delta_x,xmax) DO while x <= xmax CALL Euler(y,x,delta_x) ! use simple Euler algorithm PRINT x,y LOOP END ! end of main program SUB initial(y,x,delta_x,xmax) LET x = 1 ! initial value of x LET y = 1 ! initial value of y LET xmax = 2 ! maximum value of x LET delta_x = 0.1 ! step size PRINT " x "," y " ! print heading PRINT ! skip line PRINT x,y ! print initial values END SUB SUB Euler(y,x,delta_x) ! variables slope and change introduced for sake of clarity only LET slope = 2*x ! slope at beginning of interval LET change = slope*delta_x ! estimate of change during interval LET y = y + change ! new value of y LET x = x + delta_x ! value of x at end of interval END SUB