%% test AMSTeX/AMSMeX + qtxmath
%% this works only when amstex is loaded!!!
\input amstex

Fonty standardowe (CM+AMS CMEXTRA)
$$\eqalign{\omega &= \nu+v(x,y)\,dx + w(x,y)\,dy+d\varPsi\cr
  d\omega &=d\nu+ \left({\partial w\over \partial x}-
  {\partial v\over \partial y}\right) dx\wedge dy\cr}$$

\bigskip
\loadbold
$$\eqalign{\boldsymbol\omega &=
  \boldsymbol\nu+v\boldsymbol\{(\boldkey x,\boldkey y)\boldsymbol\}\,dx +
  w(\bold x,\bold y)\,dy+d\boldsymbol\varPsi\cr
  d\omega &=d\nu+ \left({\partial w\over \partial x}-
  {\partial v\over \partial y}\right) dx\wedge dy\cr}$$

\bigskip
\input qtxmath
\input amsqtx.tex   % ładuje amsqtx.def
\input amstbold.tex % redefinicje \loadbold, dostęp do poleceń \boldsymbol
                    % \boldkey (zauważ różnicę między \boldkey i \bold)

Fonty tx + TeX Gyre Termes
$$\eqalign{\omega &= \nu+v(x,y)\,dx + w(x,y)\,dy+d\varPsi\cr
  d\omega &\xleq d\nu+ \left({\partial w\over \partial x}-
  {\partial v\over \partial y}\right) dx\wedge dy\cr}$$

\bigskip
\loadbold
$$\eqalign{\boldsymbol\omega &=
  \boldsymbol\nu+v\boldsymbol\{(\boldkey x,\boldkey y)\boldsymbol\}\,dx +
  w(\bold x,\bold y)\,dy+d\boldsymbol\varPsi\cr
  d\omega &\boldsymbol\xleq d\nu+ \left({\partial w\over \partial x}-
  {\partial v\over \partial y}\right) dx\wedge dy\cr}$$

\bye
