1. A method for modifying a plurality of merged sub-resolution assist features, comprising: receiving a mask pattern comprising a plurality of merged sub-resolution assist features forming a T shape, the plurality of merged sub-resolution assist features comprising a segmenting sub-resolution assist feature intersecting a segmented sub-resolution assist feature at an intersection; representing each sub-resolution assist feature by an axis of the each sub-resolution assist feature to yield a plurality of axes; establishing that a segmenting axis of the plurality of axes is sufficiently long, the segmenting axis representing the segmenting sub-resolution assist feature; removing a part of the segmenting axis, the part proximate to the intersection; and converting each axis to a sub-resolution assist feature to yield a plurality of modified merged sub-resolution assist features.