Let the input alphabet be $Σ = \{1,x,=\}$
Let the stack alphabet be $\tau = \{1,\$\}$ where $\$$ is the initial stack symbol.
Let,
$q_0$ be the initial state of the PDA,
$q_f$ be the final state of PDA,
I can define a transition function for PDA like this.
$(q_0,1,\$)\rightarrow(\$1,q_1)$
$(q_1,1,1)\rightarrow(1,q_1)$
$(q_1,x,1)\rightarrow(1,q_2)$
$(q_2,1,1)\rightarrow(1,q_2)$
$(q_2,=,1)\rightarrow(1,q_3)$
$(q_3,1,1)\rightarrow(\epsilon,q_3)$
$(q_3,\epsilon,\$)\rightarrow(\$,q_f)$
Now the PDA can recognize language $L = \{1^m x 1^n = 1^{mn}\}$
But According to https://web.stanford.edu/class/archive/cs/cs103/cs103.1142/lectures/18/Small18.pdf Slide 24 this language is not Context Free.
Assume that I am quite beginner in TOC.