There were number of innovative but relatively obscure languages that came out of the first wave of cybernetics. Glushkov, one of Lyapunov's contemporaries, created a language called Analytik [1], with early support for linear algebra and symbolic differentiation. REFAL is another language that emerged during the same era and still under active development [2]. At its foundation is an alternative and surprisingly rich algebraic theory of computation based on abstract rewriting systems and so-called word problems [3].
[1]: https://link.springer.com/content/pdf/10.1007/BF01070461.pdf
[2]: https://github.com/bmstu-iu9/refal-5-lambda
[3]: https://en.wikipedia.org/wiki/Word_problem_for_groups