Implement Bottom-up GHR (buGHR)

[SamyaDaleh]

Initialize:
__________ alpha =>* epsilon
[A -> alpha dot beta, j, j]

Scan:
[A -> alpha dot a beta gamma, i, j], [a, j, j+1]
__________ beta =>* epsilon
[A -> alpha a beta dot gamma, i, j+1]

C1:
[A -> alpha dot B beta gamma, i, j], [B -> deltadot, j, k]
________ i < j < k AND beta =>* epsilon
[A -> alpha B beta dot gamma, i, k]

C2:
[A -> alpha dot B beta gamma, i, i], [C -> delta dot, i, j]
_____ i < j AND B =>* C AND beta =>* epsilon
[A -> alpha B beta dot gamma, i, j]

Source: Sikkel, Parsing Schemata p. 115