The Horsingdon Transmissions No.6: Operator Symbol

I returned to Hallowmere Playing Fields and the site of the Witching Tree earlier today to take a clearer photograph of the tree itself:

Then I discovered this:

A variant of the Operator Symbol at the edge of the fields.

In the same way that it seems to intersect with a multiplicity of other invisible and less comprehensible worlds than this, it is also often the case that the Horsingdon Triangle intersects with mythographies other than its own.