Figure 1.

Schematic illustration of our approach to semantic information. (a) The trajectory of the actual distribution (within the space of distribution over joint system–environment states) is in blue. The trajectory of the intervened distribution, where some syntactic information between the system and environment is scrambled, is in dashed red. (b) The viability function computed for both the actual and intervened trajectories. ΔV indicates the viability difference between actual and intervened trajectories, at some time τ. (c) Different ways of scrambling the syntactic information lead to different values of remaining syntactic information and different viability values. The maximum achievable viability at time τ at each level of remaining syntactic information specifies the information/viability curve. The viability value of information, ΔV_tot, is the total viability cost of scrambling all syntactic information. The amount of semantic information, , is the minimum level of syntactic information at which no viability is lost. I_tot is the total amount of syntactic information between system and environment. (Online version in colour.)