I know this is an old thread, but it popped up to the top, so here's a quick answer. The equivalent of if/then/else logic for rasters is the Con tool/statement.
Con(condition,do this if true, do this if false)
As an alternative one could use the Combine—Help | ArcGIS for Desktop tool to combine the rasters (have to be integer) and perform the analysis in the attribute table (create a new field with the result) and use the Lookup—Help | ArcGIS for Desktop tool to create the output raster based on the generated field.