Can I Delete iPhoto App and iPhoto Library?

I have 2009 imac running El Capitan. A few years ago, I migrated my iphoto library to photos. Everything fine. Can I now delete both the iphoto library (about 23 GB) and the iphoto app (about 2 GB)? I spoke to Apple rep, and he said it’s OK to delete. But, I’ve seen on some forums that the photos aren’t really duplicated, and they’re “pointing” to the same file. Just trying to clean up, so that when apple releases new imac (hopefully in 2019), and I need to transfer everything over, I don’t transfer stuff I really don’t need anymore.
Thanks for your advice.
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bob