On simplification of 4112−[134+{212−(12−13)}], we get
4112−[134+{212−(12−13)}]
=4912−[74+{52−(12−13)}]
=4912−[74+{52−12+13}]
=4912−[74+2+13]
=4912−[74+84+13] ( Adding the first two fractions inside the bracket, and taking LCM as 4)
=4912−[154+13]
=4912−[45+412] (LCM of 3 and 4 is 12 )
=4912−4912
=0