Origin for each line in Arbitrary_Precision.red from check-in 5f892713c3:

5f892713c3 2021-03-03 trnsz@pobox.c: %%%%%%%%%%%%%%%%%%%%%
5f892713c3 2021-03-03 trnsz@pobox.c: %  ARBITRARY PRECISION
5f892713c3 2021-03-03 trnsz@pobox.c: %%%%%%%%%%%%%%%%%%%%%
5f892713c3 2021-03-03 trnsz@pobox.c: 
5f892713c3 2021-03-03 trnsz@pobox.c: % Use real arithmetic
5f892713c3 2021-03-03 trnsz@pobox.c: on rounded$
5f892713c3 2021-03-03 trnsz@pobox.c: 
5f892713c3 2021-03-03 trnsz@pobox.c: % Set precision to 50 digits
5f892713c3 2021-03-03 trnsz@pobox.c: precision(50)$
5f892713c3 2021-03-03 trnsz@pobox.c: 
5f892713c3 2021-03-03 trnsz@pobox.c: % Print Pi
5f892713c3 2021-03-03 trnsz@pobox.c: pi;
5f892713c3 2021-03-03 trnsz@pobox.c: 
5f892713c3 2021-03-03 trnsz@pobox.c: % Set precision back to default (12)
5f892713c3 2021-03-03 trnsz@pobox.c: precision(12)$
5f892713c3 2021-03-03 trnsz@pobox.c: 
5f892713c3 2021-03-03 trnsz@pobox.c: % Restore precise arithmetic
5f892713c3 2021-03-03 trnsz@pobox.c: off rounded$