Hello,
I can't find this in bugzilla, so I'll assume it hasn't been reported.
The footnote at the end of section 4.4.6 on display-mode equations suggests using Insert/Math/Cases environment to enter the equation shown. However, doing so immediately results in errors in the default configuration, unless Layout/Document/Packages/Use AMS math is checked.
One or more of the following should happen:
1) AMS math should be on by default
2) The tutorial should indicate how to turn it on
3) LyX itself should detect use of AMS math features and recommend turning it on, rather than giving cryptic messages about misplaced ampersands!
I'm not subscribed, please reply directly with any feedback/flames.
Thanks, Jeremy Weatherford
