You can use the ELEMENTS command to see which elements you are currently channeling.
You can use RELEASE by itself to release all elements currently being channeled, or you can specify a specific element to release by name. For instance, you can prep pyromancy three times, cast a few tier-3 firebolts, then release pyromancy once and prep geomancy to result in now channeling pyro/pyro/geo and being able to toss some lavabolts.
Example:
Oh, and as seen above, lavabolt now results in a damage-over-time effect. Fun.pyro
Your hands glow with fiery light as you begin channeling the element of fire.
Roundtime: 3 seconds.
geo
Your hands glow with amber light as you weave the element of earth into your conjuration.
Roundtime: 3 seconds.
cryo
Your hands glow with pale blue light as you weave an intense cold into your conjuration.
Roundtime: 3 seconds.
elements
You are currently channeling the following elements:
Fire
Earth
Cold
cast dummy
You hurl a jagged spear of obsidian at an animated training dummy.
A jagged spear of obsidian hurtles toward an animated training dummy.
Ranged: 232 vs Dodge: 100
163 pierce damage!
A strike to the head!
The obsidian spear shatters into hundreds of shards!
Roundtime: 3 seconds.
Your channeling of elements continues to steadily drain your energy.
You're feeling a little winded.
release cryo
You remove the element of cold from your conjuration.
pyro
Your hands glow with fiery light as you weave the element of fire into your conjuration.
Roundtime: 3 seconds.
element
You are currently channeling the following elements:
Fire
Earth
Fire
Your channeling of elements continues to steadily drain your energy.
You're feeling tired.
cast dummy
You hurl a glob of lava at an animated training dummy.
A glob of lava hurtles toward an animated training dummy.
Ranged: 208 vs Dodge: 100
17 heat damage!
A strike to the neck!
An animated training dummy is splattered by searing lava!
Roundtime: 3 seconds.
The lava upon an animated training dummy continues to burn!
14 heat damage!
A strike to the neck!
Your channeling of elements continues to steadily drain your energy.
You're feeling exhausted! You'd better rest soon or you could collapse.
You are unable to continue channeling elements due to exhaustion.