"Design check example
#def check$(s$; f$)
	#if s$ < f$
		'<p>Design check:'s$'&le;'f$'<span class="ok">The check is satisfied ✔</span>
	#else
		'<p>Design check:'s$'&gt;'f$'<span class="err">The check is NOT satisfied ✖</span>
	#end if
#end def
'
'Stress -'σ = 200MPa
'Resitance -'f_y = 205MPa
check$(σ; f_y)
'
'Stress -'σ = 210MPa
check$(σ; f_y)