There's a new version of the PragmARCs for ISO/IEC 8652:2007 available.
This has minor changes to eliminate duplicated code between the
random-number pkgs. Those who have used functions to obtain values in a
range, or to obtain real values from generators that return integer
results, may have to make minor changes to their code. Threefry_Random
now has a block of comments describing the concept and expected use of
encryption-based (counter-based) RNGs, and has a new, pure function that
returns a random value to fulfill the expectations of those who have
read that counter-based RNGs can be accessed in parallel.
Jeffrey R. Carter, President
PragmAda Software Engineering