Remove TABs from src

Will also make selftest to check that they aren't introduced

Move FINITE_BIJ_COUNT_EQ to pred_setTheory to simplify FINITE_BIJ_COUNT, with miller and diningcryptos examples adjusted

Removed right-associative THEN and THEN1 in lebesgueScript

Merged more countable theorems into pred_setTheory

Use standard (>>, >-, >|) symbolic connectives for THEN*

This is done under src/, replacing Joe Hurd's earlier versions of the
same which were ++, >> and << respectively. His proofs also
occasionally rely on the fact that he made >> and >|
right-associative, which is a great idea. His symbols are inherently
bad but they clash with existing practice, and there seems to be a
good argument to trying to keep material in src reasonably
consistent. (Using >> for THEN1 instead of THEN is particularly
confusing given our current practice.)

Get core HOL to build with new definition of "by"

Progress with github issue #407

Fix probability theories in light of pat_assum rename

Delete trailing whitespace in src/

This needs doing periodically, and is best done to a whole bunch of files
at once.

Extend simplifier's treatment of abbrevs to handle abstractions better

added finite_support_integral_reduce

Delete trailing whitespace in src/

Integral on extended-real numbers [-Inf, +Inf]

Delete trailing whitespace in src/

modified prob theories according to #69

Delete src/probability's copy of BIGINTER constant; use standard one.

Updated files for version in repository

Start of work to incorporate Concordia probability theory.

Added Probability Theory