The algebra of sets has, basically, two different types of symbols. One type of symbol (∩, ∪, +, −) defines another set from two other sets. A second type of symbol (⊆, ⊂, =, ≠) makes a proposition about two sets. When the construction of these two types of symbols is based on the same four-dot matrix as the logic symbols described in a previous paper, the three symbol types then dovetail together into a harmonious whole that greatly simplifies derivation in the algebra of sets.