A landscape designer has available two trees each of eight different species — linden, maple, pine, quince, redbud, spruce, tupelo, and walnut— from which a selection must be made for planting at two different locations. For planting at each location, the designer will select exactly four trees, representing four different tree species, according to the following conditions:
If quince is planted at location 1, spruce cannot be planted at location 2.
If linden and quince are planted at location 1, pine must be planted at location 2.
If pine is planted at location 2, quince and tupelo must be planted at location 1.
Spruce cannot be planted at location 1 unless linden and pine are planted at location 2.