 Bolzano first explains what it means that a single proposition \(s\) is derivable (ableitbar) from a set \(\sigma\) of propositions with respect to a certain sequence \(i\) of ideas (WL II, 113 ff., 198 ff.). Since Bolzano’s term ‘Ableitbarkeit’ (‘derivability’) is used nowadays in a purely syntactical sense, we use here instead the more common phrases ‘\(s\) follows from \(\sigma\) with respect to \(i\)’ or ‘\(s\) is a consequence of \(\sigma\) with respect to \(i\)’.