porsice fu'ivla

x₁ is an ordered sequence consisting of elements x₂, x₃, x₄, etc.

See porsi, ce'o, setmice, gunmace, menrece

jbovlaste

In notes:

gunmace: x₁ is a mass/group consisting of elements x₂, x₃, x₄, etc.
menrece: x₁ is among x₂, x₃, x₄, etc.
setmice: x₁ is a set (mathematical) consisting of elements x₂, x₃, x₄, etc.