49685d02_nt_Convention___iusmentis_com___Basis_in_priority_document
[Claim] A lighting arrangement comprising three lamps according to claim 1. [Benefit of priority?] Yes. A "triangular arrangement" directly discloses three lamps. No. While a triangular arrangement directly suggests three lamps, this does not mean that three lamps in other arrangements are also disclosed. Hence this claim may not omit this feature. [Basis in priority document] 
"A plurality of lamps can be installed in a device such as a flashlight to increase light output. A preferred embodiment has the lamps in a triangular arrangement."
Priority under the European Patent Convention (EPC) (in Patents > European Patent Convention @ iusmentis.com)
Basis in priority document