2004-01-12 paulson 2004-01-12 Added lemmas to Ring_and_Field with slightly modified simplification rules Deleted some little-used integer theorems, replacing them by the generic ones in Ring_and_Field Consolidated integer powers
2003-12-03 paulson 2003-12-03 Simplification of the development of Integers
2003-08-05 nipkow 2003-08-05 cleaned up
2003-03-25 berghofe 2003-03-25 New decision procedure for Presburger arithmetic.