Sstrhsrtj

Good evening.

I've got such piece of code in pdflatex:

documentclass[a4paper,12pt]{article}



usepackage[T1]{fontenc}

usepackage[polish]{babel}

usepackage[utf8]{inputenc}

usepackage{color}

setcounter{section}{-1}



defn{newline}

defq#1{$"#1"$}

defcom#1{{color[rgb]{0.25, 0.25, 0.25}//#1//}}

defaks#1{{large Aksjomat underline{#1}}}

defbel#1#2{#1 : #2}

defkon#1#2{#1 wedge #1}

defimp#1#2{#1 Rightarrow #2}

defrown#1#2{#1 iff #2}

defFA#1{bigwedgelimits_{#1}}

defClass{underline{Class}}

defUniv{underline{Univ}}

defNull{underline{null}}

defChar{underline{Char}}

defVar{underline{Var}}



begin{document}



%here is some code, without any def instruction



nn$FA{bel{K}{Class}}FA{x, y}(imp{kon{bel{x}{K}}{x = y}}{bel{y}{K}})$



%here is also some code, also without any def instruction



end{document}

Everything goes right, until this line. I don't know why, but in PDF it replaces
x = y with bel{x}{K}


I have no idea why, I'm beginner writer, who writes since few hours. Please help. I had similar behavior few hours ago, when I wanted to print date, using DTMdate. My PDF had one page with correct date, without any other text on that page except that date. Rest of document was on next page, with wrong date, in place where there should be the date from the first page. It's complicated.

But returning, why my code replaces itself and passes other code, which is not there?

Thanks, Mike.