or evaluates as true if any one of the conditions in the or statement are true. For example, given the following case fragment:
05 Feb 03 06 Oct 03 07 Nov 03 HDL [2, 5.5] 7.3* 5.6* 6.1* LDL 1.1 0.8 pending Trig 3.2 3.6 Notes 1st note 2nd note 3rd note
the following conditions will evaluate as True:
HDL is high or Trig is high (Note that only HDL is high is true)
all HDL are High or some Notes contains “on Zocor” (Note that only all HDL are high is true)
HDL is normal or (LDL is normal or Trig is normal) (Note that only Trig is normal is true)
Parentheses may be needed for conditions with more than a single or keyword.
Note: The use of the or keyword is NOT recommended in general as it goes against the RippleDown principle of only writing rules that are necessary to deal with the current case. Rather than building a single rule with the or keyword, it is generally possible to write two separate and more specific rules instead, each dealing with a different case.
For example, rather than using the rule HDL is high or Trig is high for the case fragment above, we should just use the rule HDL is high. We then make a copy of the case and edit it to illustrate the scenario of a high Trig value but normal HDL, as follows:
05 Feb 03 06 Oct 03 07 Nov 03 HDL [2, 5.5] 7.3* 5.6* 1.5 LDL 1.1 0.8 pending Trig 3.2 5.7* Notes 1st note 2nd note 3rd note
We now build the rule Trig is high which is quite specific to this second scenario.