[TUHS] Circuit design tool mentioned in AT&T Unix promotion

[Christian Dreier via TUHS <tuhs@tuhs.org>]

Hello there,

I recently watched an old Unix promotion video by AT&T on YouTube (AT&T 
Archives: The UNIX Operating System: https://youtu.be/tc4ROCJYbm0) and 
they mention a design tool for integrated circuits (apparently named 
L-Gen or lgen; timestamped link: https://youtu.be/tc4ROCJYbm0?t=1284).

Part of this software is a language implemented with YACC that appears 
to describe the behavior of digital logic, like modern hardware 
description languages, i.e. Verilog and VHDL.

Does anyone have information about this, in particular:
- Documentation
- Which projects were realized with this?
- Source code, if possible

I asked this question on retrocomputing.stackexchange.com (see 
https://retrocomputing.stackexchange.com/q/26301/26615) but so far there 
is no satisfying answer. A "Circuit Design Language" (CDL) is mentioned 
and there is some good information about it but it has another syntax 
(as shown in the video vs. the documentation about CDL) and apparently 
another purpose (description of board wiring vs. logic behavior).

Best regards,
Christian