commandline session $ 4.2.36 13 513—> cat math.html <html> <body> <msup> <mfenced> <mi>a</mi> <mo>+</mo> <mi>b</mi> </mfenced> <mn>2</mn> </msup> </body> </html> $ 4.2.36 14 514—> $ sed “s/html/HTML/g” math.html > math-new.html bash: $: command not found $ 4.2.36 15 515—> sed “s/html/HTML/g” math.html > math-new.html $ 4.2.36 16 516—> cat math-new.html <HTML> <body> <msup> <mfenced> <mi>a</mi> …