"!" " ___ !" " /...\ !" " /.=.=.\ !" " |_____| !" " _/ | \_ !" " !" "Lunar Lander!" "!" F 1000 = 'Fuel A 100 = 'Altitude R 100 = 'Range I 0 = 'Horizontal Velocity J 0 = 'Vertical Velocity G 0 3 - = 'Gravity ( "!" "### Alt=" A.! " Range=" R.! " Fuel=" F.! " HV=" I.! " VV=" J.! " Grav=" G.! " ###!" F. 'if there is fuel left [ "Horizontal Thrust? " H ? = "Vertical Thrust? " V ? = ] 0 F. - 'if out of fuel [ "Out of fuel.!" 'then no thrust H 0 = V 0 = ] I I. H. + = 'Horizontal Accel J J. G. + V. + = 'Vertical Accel A A. J. + = 'Adjust Altitude R R. I. + = 'Adjust Range 'take abs val of h and v 0 H. - 'if h < 0 [ H 0 - H. - = 'then h = - h ] 0 V. - 'if v < 0 [ V 0 - V. = 'then v = -v ] F F. V. - H. - = 'fuel = fuel - v - h 0 A. - 'if altitude < 0 [ "!!### You landed with!" "a horizontal velocity of " I.! "!" "a vertical velocity of " J.! "!" R.! " meters from the landing pad.!" 0 ^ ] ) $$