# Equations 1.2.1 is released!

Release 1.2.1 of Equations is available, as source and
through `opam`

packages `coq-equations.1.2.1+8.9`

, `coq-equations.1.2.1+8.10`

for Coq 8.9 and Coq 8.10.

The 8.10 version (only) includes support for the HoTT library (currently available
in Coq’s `extra-dev`

repository only as `coq-hott-8.10.dev`

). Install `coq-hott`

before
Equations to get a version that uses the HoTT library.
Note that only one of the HoTT variant or the standard variant can be installed
at any given time. Using `hoqtop`

or `hoqc`

, one needs to pass the following additional
options:

```
hoqtop/hoqc -I `coqc -where`/user-contrib/Equations -Q `coqc -where`/user-contrib ""
```

Then, one can import the plugin in Coq, using:

```
From Equations Require Import HoTT.All.
```

See the Reference Manual for an introduction to Equations, or the ICFP paper.

– Matthieu Sozeau