IRule - combine 2 variables with an and && statment

just a few of comments.

1) beginning in 9.4.4, $:: prefix is no longer needed to reference data group. data group is now cmp compatible.

  set group_mobile_sites $::group_web_uri_bbbMobile
  set group_web_mobile_user_agents $::group_web_mobile_user_agents

CMP Compatibility (Class / Data Group List References section)

2) string operator (eq) should be used when comparing string

Polymorphism - Making TCL operators work for you by Colin Walker

3) is this condition checking correct? i think the last elseif won't be matched.

  if { ( $redirect_to_mobile == "true" && [class match [string tolower [HTTP::uri]] starts_with $group_mobile_sites] ) } {
    HTTP::redirect "$mobile_url[HTTP::uri]"

  } elseif { ( $redirect_to_mobile == "true" && not [class match [string tolower [HTTP::uri]] starts_with $group_mobile_sites] ) } {
    pool $non_mobile_pool

  } elseif { ( $redirect_to_mobile == "true"  ) } {
    HTTP::redirect "$mobile_url[HTTP::uri]"
  }

could it be something like this?

  if { $redirect_to_mobile eq "true" } {
    if { [class match [string tolower [HTTP::uri]] starts_with group_web_uri_bbbMobile] } {
      HTTP::redirect "$mobile_url[HTTP::uri]"
    } else {
      pool $non_mobile_pool
    }
  } 

hope this helps.