namespace eval x info vars foo
} -cleanup {
    namespace delete x
} -result {}

set functions {abs acos asin atan atan2 bool ceil cos cosh double entier exp floor fmod hypot int isqrt log log10 max min pow rand round sin sinh sqrt srand tan tanh wide}
# Check whether the extra testing functions are defined...
if {!([catch {expr T1()} msg] && ($msg eq {invalid command name "tcl::mathfunc::T1"}))} {
if {!([catch {expr {T1()}} msg] && ($msg eq {invalid command name "tcl::mathfunc::T1"}))} {
    set functions "T1 T2 T3 $functions"  ;# A lazy way of prepending!
}
test info-20.1 {info functions option} {info functions sin} sin
test info-20.2 {info functions option} {lsort [info functions]} $functions
test info-20.3 {info functions option} {
    lsort [info functions a*]
} {abs acos asin atan atan2}