irb(main):027:0> term = AST::Term.new(3)
=> #<AST::Term 3>
irb(main):028:0> term[:x] = 1
=> 1
irb(main):029:0> term[:y] = 2
=> 2
irb(main):030:0> term[:z] = 1
=> 1
irb(main):031:0> term
=> #<AST::Term 3xy^(2)z>
irb(main):032:0> term.to_s
=> "3xy^(2)z"
irb(main):033:0> term.coefficient = 1
=> 1
irb(main):034:0> term.to_s
=> "xy^(2)z"
irb(main):035:0> term.monomial?
=> true
irb(main):036:0> term[:x] = 0.5
=> 0.5
irb(main):037:0> term.monomial?
=> false
irb(main):038:0> term
=> #<AST::Term x^(0.5)y^(2)z>