Composed in Hamburg in the summer of 1971, commissioned by Ongaku no Tomo Sha for its 30th anniversary. It was premiered the following year by Haruna Hirao at the 6th Japan-Germany Contemporary Music Festival. No dedication. Published by Ongaku no Tomo Sha in the same year.

The work consists of ten short fragments and a concluding section (Coda) that is almost entirely silent. It is a piece that explores various "aleatoric" elements, from the order of performance, dynamics, and tempo, to the spacing and actions between fragments. Fragment 7's score has a hole (window) through which the page underneath (representing the past or future) can be seen. Fragment 10 may be performed by inverting the score upside down, thus reversing time. Several fragments contain differential equations from theoretical physics. For instance, Fragment 1, performed at the beginning, is the Schrödinger equation from Shin'ichirō Tomonaga's multi-time formalism of quantum field theory; Fragment 6, characterized by continuous tremolos and trills, is Einstein's field equations; and Fragment 9, the quietest in the entire piece, is the Dyson expansion of the scattering operator. In this demo performance, a deterministic version is used, "without rolling dice," which systematically covers all fragments.