As part of the
set membership test, as a boolean expression:
ordinal_value in set_expression
or, as part of a for loop iterating through a set:
for ordinal_variable in set_expression do ...
When in is used as a membership test, it acts as a binary operator taking ordinal_value as its left parameter and set_expression as its right parameter and returning a boolean result which is true if set_expression contains the element ordinal_value.
When in is used as part of a for loop, it iterates
ordinal_variable over the elements contained in
set_expression, that is every ordinal_value that
would return true if tested as ordinal_value
in is defined in ISO 7185 Pascal and supported by all known Pascal variants.
Keywords, Set Operations, set, Exclude, Include, for.