Let x0 of type ι be given.
Let x1 of type (ι → ο) → ο be given.
Let x2 of type ι → ο be given.
Apply unknownprop_ef3967aea30eb796b077b0115556310bcc08bf63575294f0ec1a3f67adc468c7 with
01d88.. x0 x1 x2,
x0,
x1,
x2.
Let x3 of type ι → ι → ο be given.
The subproof is completed by applying H0.