1 7a453fce0961c2ed49455015ca21a10dac57c3d4 first preview version for Schaeffter

2 3b5ba7331eb579686d32e1c630739e23826162f4 second preview version for Schaeffter

3 9ec16cd54ab64466ba1baf213cebdf0e81a84152 third preview version for Schaeffter

4 70201774b457cebf9e4f2d722aa5a79010553d94 fourth preview version for Schaeffter

5 47af8eb539cf9f9f65df0a0150273b441c4d0c0b proof-read version for ben and james (ch234)

6 99ad9d520addf76ae1094ebd016adc196347cac6 fifth preview version for Schaeffter

7 8341092a7554b89206b2e3bed1a41bf7d0a567f0 sixth preview version for Schaeffter and Traub

8 e5033a9cbf53ac9dc42aac01cb36b3e86d42cbbe version for proof-readers

9 ba9463b43709c84e1a4263d9097b5dba431bec84 seventh preview version for Schaffter

10 ee7211546c02d5a6cf7589d1881b37a86a633bde final version which I handed in