Guard: Straight Armbar

This move starts with A having half guard control with an underhook and head control.
Assume A has top half guard on B's left leg.
From the bottom starting position, B grabs A's belt with the overhooking arm and uses their elbow+belt grip to keep A's underhook pinned. B can then use their free left arm to create space at the hip to shrimp out. Once space is created and B is on their left hip, B takes their right outside leg and places it inside A's thigh for a butterfly hook. Assuming A has left their arm for head control, B takes their free left hand (hand that is not gripping the belt) and wraps it around the outside of A's arm and grabs their own lapel. With the butterfly hook, B rolls from their left hip to the flat of their back while elevating with the butterfly hook. Elevating A with the butterfly hook makes it easier to regain guard and sets up the next part of the move. Once guard is regained, B releases the belt grip and uses their forearm to push A's face away while bring the same side leg as the gripped arm and brings it up A's back while B's bottom leg comes up to A's chest. From there, B straightens out the arm and straightens their back to get the straight armlock.