The poem
Frog = Splash (The Self − The Mind) ⁄ The Old Pond + Noise
The value of the frog is to the value of the self as the value of the noise is to the value of the mind as the value of the splash is to the value of the old pond.
Where the equation comes from
An expanded similar triangles poem sets three ratios equal — a ⁄ b = c ⁄ d = e ⁄ f — and then subtracts two of them, numerator with numerator and denominator with denominator. The proportion survives the operation. Solving what is left for one term gives the equation on the piece.
The three ratiosFrog ⁄ The Self = Noise ⁄ The Mind = Splash ⁄ The Old Pond
Subtract the first two(Frog − Noise) ⁄ (The Self − The Mind) = Splash ⁄ The Old Pond
Solved for FrogFrog = Splash (The Self − The Mind) ⁄ The Old Pond + Noise
What the expansion buys is a poem about a difference or a sum rather than a quantity — two terms held apart, and the gap between them standing in fixed ratio to a third.