The symbol ⊩ is used in modal logic (read as "forces"). ⊢, ⊨, and ⊫ are supported, so ⊩ (U+22A9) seems like a natural addition. Additionally, negated versions would be useful: ⊬ ⊭ ⊮ ⊯ (U+22AC, U+22AD, U+22AE, U+22AF).
The symbol ⊩ is used in modal logic (read as "forces"). ⊢, ⊨, and ⊫ are supported, so ⊩ (U+22A9) seems like a natural addition.
Additionally, negated versions would be useful: ⊬ ⊭ ⊮ ⊯ (U+22AC, U+22AD, U+22AE, U+22AF).