countSubmitsInWindow never saw an amountText here, so every walk test counted
submits the app must have refused. with the field passed, a refused submit no
longer buys a later double tap an alibi: without it the window reads 3, not 1.
three of the 18 frames the recorded ios run drove it down, each with the
second commit the bound is there to catch. neutering the comparison reddens
it: a second commit on 357900 went unjudged.
The counting invariant can only close its window on Home, and the iOS run
in #78 went 117 steps between two Home readings: 37 submits against a rise
of 15 transactions is no evidence about the double tap sitting inside it.
The ledger and the add-transaction screen both show the account's own
balance, and an accepted submit pops back to the ledger, so a window
bounded by those readings holds one action.
The bound is an upper one: a balance that has not moved is a commit still
in flight, a rejected submit or a tap that never landed, and none of those
is a violation. Moving by more than the one submit in the window typed is.