fixes #1734 (renaming derivable_oo_continuous_bnd)

[affeldt-aist]

Motivation for this change

fixes #1734

Checklist

• added corresponding entries in CHANGELOG_UNRELEASED.md

• added corresponding documentation in the headers

Reference: How to document

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[t6s]

The changes look consistent.

The capital letters L and R in those identifiers look a bit intimidating.
If this is the result of some previous discussion, I will approve this PR, not resuming the issue.
If not, what about naming them like derivable_oo_continuous_cc, derivable_oy_continous_cy, etc.?

[t6s]

The changes look consistent.

The capital letters L and R in those identifiers look a bit intimidating. If this is the result of some previous discussion, I will approve this PR, not resuming the issue. If not, what about naming them like derivable_oo_continuous_cc, derivable_oy_continous_cy, etc.?

@affeldt-aist suggested using these names (the ones I listed) for lemmas rather than predicates, and I approved that.