Curry: An Integrated Functional Logic Language

• The sequence [e1..e2] denotes the finite list [e1,e1+1,e1+2,...,e2]. Note that the list is
empty if e1 > e2.
• The sequence [e1,e2..] denotes the infinite list [e1,e1+i,e1+2*i,...] with i = e2 −e1. Note
that i could be positive, negative or zero.
• The sequence [e1,e2..e3] denotes the finite list [e1,e1+i,e1+2*i,...,e3] with i = e2 − e1.
Note that e3 is not contained in this list if there is no integer m with e3 = e1 + m ∗ i.
For instance, [0,2..10] denotes the list [0,2,4,6,8,10].
5.2 List Comprehensions
The second compact notation for lists are list comprehensions. They have the general form
[ e | q1 ,..., qk ]
where k ≥ 1 and each qi is a qualifier that is either
• a generator of the form p