Boil yams until half-cooked; then cool with cold running water.
Peel and slice.
Peel, core, and slice apples.
Combine yam and apple slices in a bowl.
Sprinkle with lemon juice.
Combine brown sugar replacement, fructose, cinnamon, ginger, salt, and cloves in a bowl.
Stir to mix.
Layer a third of the yam-and-apple slices mixture in the bottom of a 8 or 9 inch (20 or 23 cm) pastry-lined pie pan.
Sprinkle with a third of the sugar replacement mixture; then dot with 1 tsp (15 mL) of the margarine.
Repeat these layers two more times.
Pour skim milk over entire surface.
Adjust top crust and seal edges securely.
Bake at 425°F (220°C) for 35 to 45 minutes or until yams become soft.