dG differential ghost adds a new differential equation y'=a(x)*y+b(x) to [{x'=f(x) & Q}]P which, when cleverly chosen, simplifies the analysis of the resulting system after rephrasing P in the resulting [{x'=f(x), y'=a(x)*y+b(x) & Q}]P. This technique is very effective to accumulate facts about the historical evolution of the ODE.

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