OASL

Oleic acid SL at a final concentration of 10 mg/mL (no inherent QSI activity of OASL at this concentration) helped emulsify the oils completely before addition to the agar wells in the test plate.

All the synthesized EOSLs were analyzed by TLC and they were compared with an OASL control.

Interestingly it was observed that oils that were not showing any QSI activity before, either alone or in combination with OASL, became potent inhibitors of quorum sensing mediated phenotypes upon transformation into their corresponding EOSLs (Table 1).

FTIR analysis demonstrated that synthesized EOSLs show certain peaks similar to those of OASL; however, certain new peaks could be seen in the spectra of the synthesized EOSLs.

The theoretical issue is whether any proof of a sentence can, at least in theory, be replaced by a proof in OASL .

certain theorems in Hyperproof cannot be proven in OASL alone (Barwise and Etchemendy [1994], p.

Indeed they have shown that there are theorems provable in Hyperproof that cannot be proved in OASL (for the specific OASL in question).

If a suitably expressive sentential language were provided, Hyperproof would he improved and also then it would have no advantage over OASL. Thus Barwise and Etchemendy seem to be trying to make a virtue out of a shortcoming.