exactly evaluates as true if a statement is true some specified number of episodes. For example, given the following case fragment:
05 Feb 03 06 Oct 03 07 Nov 03 HDL [2, 5.5] 7.3* 4.8 6.1* LDL 1.1 0.8 pending Trig 2.2 0.5*
exactly 2 HDL are high
exactly 1 LDL is “pending”
exactly 1 Trig is not numeric