Logic Column 12: Logical Verification and Equational Verification

Note from the Editor: There were some errors in the last article of the Logic Column. Thanks to Claudia Zepeda for spotting them. They have been corrected in the online version of the article, available from the CORR archive at http://arxiv.org/abs/cs.LO/0502031. All articles published in this column are archived at CORR; the following URL will return them all: http: //arxiv.org/find/grp_cs/1/ti:+AND+logic+column. I am always looking for contributions. If you have any suggestion concerning the content of the Logic Column, or even better, if you would like to contribute by writing a survey or tutorial on your own work or topic related to your area of interest, feel free to get in touch with me.