The annotated expression evaluates to an integer whose value is at least 2 less than the lengths of all the given sequences.

For example, an expression with type @LTLengthOf({"a", "b"}) is less than or equal to both a.length-2 and b.length-2. Equivalently, it is less than both a.length-1 and b.length-1. The sequences a and b might have different lengths.

In the annotation's name, "LTOM" stands for "less than one minus".

@LTOMLengthOf({"a"}) = @LTLengthOf(value={"a"}, offset=1), and
@LTOMLengthOf(value={"a"}, offset=x) = @LTLengthOf(value={"a"}, offset=x+1) for any x.