Table 1 Types of interactions with those representation by links, and examples in real systems.

Excitatory

\(X\mathop{\longrightarrow }\limits^{+}Y\)

Signaling in neuronal and gene regulatory nets, commensalism, donation

Inhibitory

\(X\mathop{\longrightarrow }\limits^{-}Y\)

Signaling in neuronal and gene regulatory nets, amensalism, harassment

Cooperative

\(X\underset{+}{\overset{+}{\rightleftharpoons }}Y\)

Positive feedback, mutualism, cooperation, friendship

Predatory

\(X\underset{+}{\overset{-}{\rightleftharpoons }}Y\)

Negative feedback, predation, parasitism, exploitation, selfish actions

Competitive

\(X\underset{-}{\overset{-}{\rightleftharpoons }}Y\)

Mutual inhibition, competition, antagonism