Turba Tol Hol-Hol Tol. Venecia, Italia, 2022

Importing HOL into Isabelle/HOL

We developed an importer from both HOL 4 and HOL-light into Isabelle/HOL. The importer works by replaying proofs within Isabelle/HOL that have been recorded in HOL 4 or HOL-light and is therefore completely safe. Concepts in the source HOL system, that is types and constants, can be mapped to concepts in Isabelle/HOL; this facilitates a true integration of imported theorems and theorems that ar...

Richard S.J. Tol

For a long time, it was politically incorrect to speak about adaptation to climate change, because it presumably implies accepting defeat in the battle against evil emissions (Burton, 1994). This has changed, perhaps because scientists repeatedly pointed out that climate change cannot be altogether avoided even if we try very hard (Parry et al., 1998; Wigley, 1997), and perhaps because George W...

Taking the hol out of HOL

We describe a systematic approach to building tools for the automated analysis of specifications expressed in higher-order logic (hol) independent of a conventional, interactive theorem proving environment. In contrast to tools such as HOL and PVS, we have taken “the hol out of HOL” by building automated analysis procedures from a toolkit for manipulating hol specifications. Our approach elimin...

Towards HOL 2000 ? 1 Towards HOL 2000 ?

Deep VLT spectroscopy of the blue compact dwarf galaxies Tol 1214 – 277 and Tol 65 ⋆

We present VLT spectroscopic observations with different spectral resolutions and different slit orientations of the two metal-deficient blue compact dwarf (BCD) galaxies Tol 1214–277 and Tol 65. The oxygen abundances in the brightest H ii regions of Tol 1214–277 and Tol 65 are found to be 12 + log O/H = 7.55 ± 0.01 and 7.54 ± 0.01, or Z⊙/24 . The nitrogen-to-oxygen abundance ratios in the two ...