[TUHS] execl and execv, first appearance in unix

Greetings, I was reviewing a manual page update and came across an ambiguous answer to a question that came up, so I thought I'd ask here. execl and execv first appear in our extant unix man pages in V4. The v3 and v2 man pages don't have this listed at all. Case closed, right? It appeared in V4. However, the Dennis_v1/unix72 tree has execl.s and execv.s in them. Diving back into the history on Warren's github account, https://github.com/DoctorWkt/unix-jun72/tree/master/src says they come from: "The files in lib/ come from the libc.sa file which is on the last1120c.tar.gz tap(I) tape image, also at the same URL, and form the C library for the above compiler." and "from a working C compiler for 2nd Edition UNIX." which suggests that it may have been in V2 or maybe even V1. It's first use in Unix appears to be V5, but the extant pre-v5 code is so fragmentary it's hard to know for sure. It's not mentioned in section II or section III of v1, v2 or v3. Does anybody know for sure, or can provide more insight into the last1120c.tar.gz file to help disambiguate? Warner