Does convoke let you tap a creature with summoning sickness to reduce a spell's cost?

Convoke (CR 702.51) lets you tap untapped creatures you control as you cast a spell to reduce its cost — each tapped creature pays for one generic mana or one mana of that creature's color. However, this tap action is subject to the same rules as any other use of the tap symbol.

CR 302.6 (summoning sickness) states that a creature cannot attack or use activated abilities with the tap symbol (or untap symbol) in their cost unless it has been under your control continuously since the beginning of your most recent turn. Convoke explicitly uses the tap symbol when you tap a creature for it (CR 702.51b), so summoning sickness applies.

CR 702.51b confirms that tapping a creature for convoke follows the same rules as tapping for an activated ability with a tap symbol in its cost — meaning a creature that just entered the battlefield this turn cannot be tapped for convoke unless it has haste (CR 702.10).

Example: You cast a 4/4 creature on your turn. On that same turn, you try to cast Chord of Calling and want to tap that 4/4 to help pay the convoke cost. You cannot — it has summoning sickness. If it had haste, you could tap it.

The exception: if the creature has haste (CR 702.10), summoning sickness does not apply, and it can be tapped for convoke even on the turn it entered the battlefield.