What skill did John Spartan learn while in cryogenic prison in the 1993 film "Demolition Man"?

In the 1993 film "Demolition Man" Los Angeles police officer John Spartan (played by Sylvester Stallone) and his nemesis Simon Phoenix (portrayed by Wesley Snipes) are cryogenically frozen in 1996 as punishment for Phoenix's kidnapping and the deaths of the kidnap victims. Spartan was blamed for the deaths and sentenced along with Phoenix. Each undergo behavioral modifications while frozen. John Spartan learns knitting, while Phoenix learns numerous skills that include martial arts, weapons training and others that aid in his escape from the cryogenic prison while at a parole hearing.

Simon Phoenix's skills were modified in order to aid the architect of the society in 2032, Dr. Raymond Cocteau, as someone who could rid the remaining "criminal element", people that live under the city, outside the law. The current police force are unable to cope with this type of criminal, release John Spartan to stop Phoenix. Ultimately Phoenix is stopped, Dr. Cocteau is dead and the foundation of the society he created destroyed.

The film also starred Sandra Bullock, Denis Leary and Nigel Hawthorne. The film received mixed reviews and collected US$159 million at the box office on a budget estimated at US$59-77 million.