cross-reference to symbiyosys in README,

mentioning that Formal Correctness Proofs may be written and run from nmigen

diff --git a/README.md b/README.md
index aac1e0c6642612a38f68b7401f3274e0f9cd93f6..60b870ffdb902965a06b9877bf73763927325bc9 100644 (file)
--- a/README.md
+++ b/README.md
@@ -30,7 +30,8 @@ and elegant designs.
 
 Other nMigen libraries are built on FHDL and provide various tools and
 logic cores. nMigen also contains a simulator that allows test benches
-to be written in Python.
+to be written in Python, and writing and running Formal Correctness Proofs
+in nMigen are also supported, using [Symbiyosys][].
 
 See the [docs/](docs/) folder for more technical information.
 
@@ -49,6 +50,7 @@ The development of nMigen has been supported by [M-Labs][] and
 [yosys]: https://yosyshq.net/yosys/
 [m-labs]: https://m-labs.hk
 [lambdaconcept]: http://lambdaconcept.com/
+[symbiyosys]: https://symbiyosys.readthedocs.io/
 
 ### HLS?