 In this way, the opponent may (but does not have to) examine the well formation of the thesis with the challenge “\(\rqst_{\bprop}\)” before starting to ask for reasons. The formation rules for logical constants and for falsum are given in the following table. Notice that a statement “\(\bot: \bprop\)” (which reads \(\bot\) is a proposition) cannot be challenged; this is the dialogical account for falsum “\(\bot\)” being by definition a proposition.