( A
  =     m n value key eq chain
      , find insert future stack va val
    .   ( chain
        =   key future skey
          .   !arg:(?key.?future)
            & str$!key:?skey
            & (cache..insert)$(!skey..!future)
            &
        )
      & (find=.(cache..find)$(str$!arg))
      & ( insert
        =   key value future v futureeq futurem skey
          .   !arg:(?key.?value)
            & str$!key:?skey
            & (   (cache..find)$!skey:(?key.?v.?future)
                & (cache..remove)$!skey
                & (cache..insert)$(!skey.!value.)
                & (   !future:(?futurem.?futureeq)
                    & (!futurem,!value.!futureeq)
                  |
                  )
              | (cache..insert)$(!skey.!value.)&
              )
        )
      & !arg:(?m,?n)
      & !n+1:?value
      & :?eq:?stack
      &   whl
        ' ( (!m,!n):?key
          &     (   find$!key:(?.#%?value.?future)
                  & insert$(!eq.!value) !future
                |   !m:0
                  & !n+1:?value
                  & ( !eq:&insert$(!key.!value)
                    |   insert$(!key.!value) !stack:?stack
                      & insert$(!eq.!value)
                    )
                |   !n:0
                  &   (!m+-1,1.!key)
                      (!eq:|(!key.!eq))
                |   find$(!m,!n+-1):(?.?val.?)
                  & (   !val:#%
                      & (   find$(!m+-1,!val):(?.?va.?)
                          & !va:#%
                          & insert$(!key.!va)
                        |   (!m+-1,!val.!eq)
                            (!m,!n.!eq)
                        )
                    |
                    )
                |   chain$(!m,!n+-1.!m+-1.!key)
                  &   (!m,!n+-1.)
                      (!eq:|(!key.!eq))
                )
                !stack
            : (?m,?n.?eq) ?stack
          )
      & !value
  )
& new$hash:?cache