You use the concatenation operator (_) to combine multiple strings into a single string.
USER>set a = "Interoperable", b = "Reliable", c = "Intuitive", d = "Scalable", e = " ", f = "IRIS:"
USER>set s = f _ e _ a _ e _ b _ e _ c _ e _ d
USER>write s
IRIS: Interoperable Reliable Intuitive Scalable
USER>
