Herbie can generate alternatives that are the same as the initial equation

[acoustoelectrically]

This can be seen here https://herbie.uwplse.org/demo/806f578ab5283453deef2aa802d79d140ffbd31c.1a83c9f5186db102b678a2d5f869f99992469071/graph.html (alternative 5 is the same as the initial equation)

https://herbie.uwplse.org/demo/b11dc8848070d0b9ef0d692f2cf569295d11a9c1.1a83c9f5186db102b678a2d5f869f99992469071/graph.html (alternative 7 is the same as the initial equation)

https://herbie.uwplse.org/demo/c933c3e3b77b8183124f92cf32455d4f99e5cc6e.1a83c9f5186db102b678a2d5f869f99992469071/graph.html (alternative 1 and the initial equation)

https://herbie.uwplse.org/demo/b0a851f8ae2e54556234e5ab82567aa2b2ef066e.1a83c9f5186db102b678a2d5f869f99992469071/graph.html

We could just hide alternatives that are the same as the input, and if there are no alternatives to be generated, it could probably say "no alternatives found" (like when entering the number "1")