Permanent problem IDPPL 156
Formal languages
Given context-free L₁ ⊆ L₂ with infinite difference, must there be a context-free L₃ strictly interpolating them with both remaining differences infinite?
Given context-free L₁ ⊆ L₂ with infinite difference, must there be a context-free L₃ strictly interpolating them with both remaining differences infinite?
Personal cash offer stated in Shallit’s official talk. The live talks page records subsequent updates, including a paid solution to one omitted problem; confirm claim procedure with the sponsor before relying on the award.