database - Projection in Relational Algebra -

there table called person has name, age, weight columns.

name: a, b,c,d,e  age: 34,21,23,34,12 

how can use relational algebra project names ages 34?

if remember relational algebra correctly should this:

π name (σ age = 34 (person))  

where π projection , σ selection. equal select name person age = 34in sql , can read from person select relations age 34 , show name.

the formatting options here rather limited doesn't quite should...