[18Rhl] Clarification of river crossing rule

[slapphappyjazz]

Wolfram has clarified the rule for tracing routes through the Rhine Metropolis green tiles. See https://boardgamegeek.com/thread/3448927/article/45769379#45769379

[ollybh]

@slapphappyjazz Can you please summarise what needs to be changed is the 18xx.games implementation of 18Rhl?

[slapphappyjazz]

@ollybh I don't know what is implemented at present. If the implementation follows the summary by Bruce Murphy at the following URL, then it will need to be changed as per the clarification from Wolfram that I linked to in the original post.
https://boardgamegeek.com/thread/2553217/article/39604933#39604933 Bruce's summary says that a route only needs to cross the Rhine in the case that the company's token in that metropolis is the only one on the route. The 18Rhl rulebook adds the case that it must cross the Rhine if the company needs to access an open city circle on the other side in order to run through the hex; and Wolfram's clarification adds the case that it must cross the Rhine if the company needs to access its station marker on the other side in order to run through the hex.

I logged this issue so that someone could check the code. I don't have an example game, unfortunately.