Yes. However you need to define what you mean by "call". It has a specific meaning within programming languages, which is not what it sounds like you're wanting to do.
If by "call" you mean "retrieve the value of", then yes. However I have to fix some apparent assumptions that change the answer, depending on what you think you're doing.
Code:
Main.Weapon.Type = GreatAxe
In this case, Main.Weapon.Type is assigned the value of GreatAxe. Note that GreatAxe is not a string in and of itself, it's a label. Being a label, it represents a variable. If you have assigned GreatAxe a value, that value will be assigned to Main.Weapon.Type. If you have not assigned GreatAxe a value, then Main.Weapon.Type will be assigned the value of nil with the above statement.
If your intent is to assign the value "GreatAxe" to the variable Main.Weapon.Type, then GreatAxe needs to be a string: "GreatAxe", not a label: GreatAxe.
Same with sword.
Code:
if spell.wsA == '[world.day_element] and or [world.weather_element]' then
You have enclosed the comparson in single quotes. That makes the -entire- quote a string. You're comparing the value of the spell.wsA variable with the literal string, '[world.day_element] and or [world.weather_element]'. That comparison will never be true.
It appears you want to create some sort of vague logical comparison using the values of world.day_element and world.weather_element, and combine them with and/or. The way you've written it is completely non-functional, though.
Further, spell.wsA gives you the skillchain property of the spell, not the element of the skillchain property. That means you need to map it onto a list of elements before you can use it to compare with the day or weather element.
A quick (incomplete) bit of coding to roughly do what you're asking would be:
Code:
skillchain_elements = get_skillchain_elements(spell.wsA, spell.wsB, spell.wsC)
-- assuming get_skillchain_elements returns a set S{}
if skillchain_elements:contains(world.day_element) or skillchain_elements:contains(world.weather_element) then
-- stuff
end
And then you'd need a function to convert skillchains to elements (eg: Fragmentation -> S{Wind, Lightning}; etc).
The answer to your question is no, though the example you give to explain your question doesn't match what your question seems to be asking. Overall I have no idea if I even know what you're asking.