bridcrit: Bridge interval criterion function
In balachia/pcPack: Producer Categories Paper Package

General criterion is 0 = M' + ( 1/2 * V' * ( -Ed2u/Edu ) ) Logged criterion is 0 = -log M' + log(1/2 V') + log( -Ed2u/Edu ) Bridge criterion: M' = (Wr-Wl)/(xr-xl) + c'(delta) - c'(dbar) Bridge criterion: V' = (dbar-delta)/(xr-xl) * sigma^2

1	bridcrit(delta, xl, xr, Wl, Wr, sigma = 1, b = 1, log = TRUE, ...)

`delta`	distance from left point
`xl`	position of left point
`xr`	position of right point
`Wl`	value at left point
`Wr`	value at right point
`sigma`	brownian walk sigma parameter
`b`	utility function b parameter
`log`	use logged criterion?
`...`	additional arguments to criterion subfunctions