.PS include(pstricks.m4) scale=25.4 cct_init vsp=25 hsp=25 define(`termrad_',`sourcerad_/4') define(`terminal',`circle rad termrad_') O: (0,0) move to O IS: source(up_ vsp,I,,R);llabel(,i_s,);rlabel(,\np{0.5}\;\text{A},) line right hsp { dot(at Here) R1: resistor(down_ to (Here.x,O.y));rlabel(,R_1,);llabel(,10\;\Omega,) dot(at Here)} line right hsp { line right hsp*.75 TA: terminal} dot(at Here) R1: resistor(down_ to 1/2 between Here and (Here.x,O.y));rlabel(,R_2,);llabel(,15\;\Omega,) VS: source(down_ to (Here.x,O.y),V,,R);rlabel(,v_s,);llabel(,\np{4.5}\;\text{V},) dot(at Here) { line right hsp*.75 TB: terminal} line to O "$a$" at TA.n above "$b$" at TB.s below .PE