It seems that Spot cannot parse implication and equivalent operators in prefix order. I tried on both my local machine and the online translator.

The installed Spot version is 2.11.1.

The commands are

- local: spot.formula("-> a b")

- online translator: type in -> a b

Error message: syntax error, unexpected implication operator

Thank you very much for your help and creating the conda package for Spot, that makes the installation very convenient! Happy holidays!

Best,
Jason