; Comment Begin reversible block Break to end of loop Break to end of switch
Case Default Disable cancel test at loops Else
Else If calculation Else If flag false Else If flag true Enable cancel test at loops
End For End If End reversible block End Switch
End While For each line in list For field value If calculation
If canceled If flag false If flag true Jump to start of loop
Repeat Switch Until break Until calculation
Until flag false Until flag true While calculation While flag false
While flag true