is, is not

is evaluates as True if the left hand expression equals the right hand expression. Similarly is not evaluates as True if the left hand expression does NOT equal the right hand expression. For example, given the following case fragment:

Cholesterol     7.3    5.6    6.1
Triglyceride    1.1    0.8    pending
HDL                    2.2    1.9
HDM                    3.3    1.9

Cholesterol is 6.1
Triglyceride is “pending”
HDL is not 2.2
HDL is HDM
HDL is not Cholesterol

See also: are, are not