updated from proofreading

sed.js

@@ -0,0 +1,23 @@
+const fs = require("fs");
+
+const src = fs.readFileSync("content_pre.tex").toString();
+
+src.replace(`\\begin{verbatim}
+      instr  1 ; instrument with fabricated reson:
+la1   init   0 ; clear feedbacks
+la2   init   0 ; at start only
+i3    = exp(-6.28 * p6 / 10000)               ; set coef 3
+i2    = 4*i3*cos(6.283185 * p5/10000) / (1+i3); set coef 2
+i1    = (1-i3) * sqrt(1-1 - i2*i2/(4*i3))     ; set coef 1
+a1    rand   p4                               ; source signal
+la3   =      la2                              ; feedback 2
+la2   =      la1                              ; feedback 1
+la1   =      i1*a1 + i2 * la2 - i3 * la3      ; 2nd order difference eqn
+      out    la1
+      endin
+
+      instr 2 ; this instr does same as above
+a1    rand   p4                               ; source signal
+a1    reson  a1,p5,p6,1                       ; 2nd order recursicve filter
+      endin
+\\end{verbatim}`,``)