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Equation 17 · Part 7 · The Type Chart Is a Payoff Matrix, and the Metagame Only Half-Solves It

subscript

ϕ(x)=∑ixifi(x)\phi(x) = \sum_i x_i f_i(x)
subscript

What this part means

The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.

Its job in the formula

A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.

The passage around this formula

Run the continuous replicator equation on the resulting eight-strategy zero-sum game: x˙i\dot{x}_i = xix_i(\big(fi(x)f_i(x) - ϕ(x)\phi(x))\big) , where fi(x)f_i(x) = ∑j\sum_j xjx_j\, U(i,j) is species i ’s expected payoff against the current population mix and ϕ(x)\phi(x) = ∑i\sum_i xix_i fi(x)f_i(x) is the population’s average payoff. Starting from a uniform mix across all eight and integrating to convergence, the system does not settle into anything resembling the real ladder’s spread. It collapses toward a near-monopoly: Great Tusk at 87.71% of the stationary mix, Dragonite at 6.50%, Kingambit at 5.76%, and the other five species asymptoting toward zero, Gholdengo included, despite Gholdengo sitting in second place on the…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

Open the illustrated subscripts: which member of a family? guide →

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