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Here's the info. from Answers. com
for all intents and purposes: Information from Answers.comIdioms: to all intents and purposes
Also, for all intents and purposes; for all practical purposes. In every practical sense, virtually. For example, For all intents and purposes the case is closed, or For all practical purposes the Vice-President is the chief executive while the President is in the hospital. The first phrase, dating from the 1500s, originated in English law, where it was to all intents, constructions, and purposes. A shorter synonym is in effect, def. 1.