Logiweb bibliography of prop calc

Logiweb bibliography of prop calc in pyk

[0] prop calc
[1] base
[2] check

The pyk compiler, version 0.grue.20050502 by Klaus Grue,
GRD-2005-06-05.UTC:08:46:27.673984 = MJD-53526.TAI:08:46:59.673984 = LGT-4624678019673984e-6