Answered
How to define two parameters 'a' and 'b' in such a way that 'a' can assume any of the values in the list {a_1, a_2, ..., a_n} if at least one of a_1, a_2, ..., a_n is defined and 'b' also can assume values from the same list {a_1, a_2, ..., a_n} if at least one of a_1, a_2, ..., a_n is defined, but 'a' is always less than 'b'?
The same question 
Idea:
Sort your list A={a_1, a_2, ..., a_n}
Choose your element a and set c:= indexOf(a,A)
Create B:=Take(A,c+1) and choose b ∈ B.
Greetings
mire2
Comments have been locked on this page!